JUNO ONLINE SERVICES INC
S-1/A, 1999-05-07
COMPUTER PROGRAMMING, DATA PROCESSING, ETC.
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<PAGE>
   
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 7, 1999
    
                                                      REGISTRATION NO. 333-73449
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
   
                                AMENDMENT NO. 2
                                       TO
                                    FORM S-1
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933
    
 
                           JUNO ONLINE SERVICES, INC.
             (Exact Name of Registrant as Specified in its Charter)
 
<TABLE>
<S>                               <C>                               <C>
            DELAWARE                            7370                           13-3914547
(State or Other Jurisdiction of     (Primary Standard Industrial            (I.R.S. Employer
 Incorporation or Organization)     Classification Code Number)          Identification Number)
</TABLE>
 
                            ------------------------
 
                                 1540 BROADWAY
                            NEW YORK, NEW YORK 10036
                                 (212) 597-9000
              (Address, Including Zip Code, and Telephone Number,
       Including Area Code, of Registrant's Principal Executive Offices)
 
                         ------------------------------
 
                              MR. CHARLES E. ARDAI
                                   PRESIDENT
                           JUNO ONLINE SERVICES, INC.
                                 1540 BROADWAY
                            NEW YORK, NEW YORK 10036
                                 (212) 597-9000
           (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)
 
                         ------------------------------
 
                                   COPIES TO:
 
<TABLE>
<S>                                         <C>
         ALEXANDER D. LYNCH, ESQ.                      JOHN W. WHITE, ESQ.
         BRIAN B. MARGOLIS, ESQ.                     CRAVATH, SWAINE & MOORE
     BROBECK, PHLEGER & HARRISON LLP                     WORLDWIDE PLAZA
       1633 BROADWAY, 47(TH) FLOOR                      825 EIGHTH AVENUE
         NEW YORK, NEW YORK 10019                    NEW YORK, NEW YORK 10019
              (212) 581-1600                              (212) 474-1000
</TABLE>
 
                            ------------------------
 
    APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after the effective date of this Registration Statement.
 
    If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box. / /
 
    If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. / /
 
    If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /
 
    If this Form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. / /
 
   
    If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. / /
    
                            ------------------------
 
    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SECTION 8(A), MAY
DETERMINE.
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE MAY
NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS
EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER TO SELL THESE SECURITIES AND IT IS
NOT SOLICITING AN OFFER TO BUY THESE SECURITIES IN ANY STATE WHERE THE OFFER OR
SALE IS NOT PERMITTED.
<PAGE>
   
                    SUBJECT TO COMPLETION, DATED MAY 7, 1999
    
 
PROSPECTUS
 
                                        [LOGO]
 
                                6,500,000 SHARES
 
                           JUNO ONLINE SERVICES, INC.
                                  COMMON STOCK
 
                                ---------------
 
    We are selling 6,500,000 shares of our common stock. The underwriters named
in this prospectus may purchase up to 975,000 additional shares of our common
stock to cover over-allotments.
 
   
    This is an initial public offering of common stock. Juno Online Services,
Inc. currently expects the initial public offering price to be between $11.00
and $13.00 per share. Our common stock has been approved for quotation on the
Nasdaq National Market under the symbol "JWEB".
    
 
                            ------------------------
 
    INVESTING IN THE COMMON STOCK INVOLVES RISKS. SEE "RISK FACTORS" BEGINNING
ON PAGE 9.
 
    Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.
 
                            ------------------------
 
<TABLE>
<CAPTION>
                                                                                     PER SHARE         TOTAL
                                                                                   --------------  --------------
<S>                                                                                <C>             <C>
 
Initial Public Offering Price....................................................  $               $
Underwriting Discount............................................................  $               $
Proceeds to Juno Online Services, Inc............................................  $               $
</TABLE>
 
    The underwriters are offering the shares subject to various conditions. The
underwriters expect to deliver the shares to purchasers on or about
            , 1999.
 
                            ------------------------
 
SALOMON SMITH BARNEY
               BEAR, STEARNS & CO. INC.
                               PAINEWEBBER INCORPORATED
 
          , 1999
<PAGE>
Description of graphics on inside front, gatefold and back cover pages of
prospectus:
 
Inside Front Cover:
 
[JUNO]                                                               [Juno Logo]
 
The caption at the top of the page reads:
 
"Our multiple service levels and easy-to-use, intuitive software are designed to
attract a broad spectrum of users by offering a gradual migration path onto the
Internet."
 
The picture in the upper right corner depicts the "Juno Web" portion of the Juno
Web site. The sidebar text reads:
 
"Juno Web
Full Internet access through either of the two most popular Web browsers."
 
The picture in the middle depicts the "Juno Gold" portion of the Juno Web site.
The sidebar text reads:
 
"Juno Gold
Enhanced e-mail: send pictures, spreadsheets, word processor files, and more."
 
The picture in the lower left corner depicts the "Basic Free E-mail" portion of
the Juno Web site. The sidebar text reads:
 
"Juno's Basic Service
Basic dial-up Internet e-mail, provided to the end user for free."
 
The caption at the bottom of the page reads:
 
"Juno Online Services, Inc. is a leading provider of Internet-related services
to millions of computer users throughout the United States. Our services and
software have been designed with special attention to the needs of consumers who
are just now beginning to explore the Internet. Subscribers who are not yet
ready to use or pay for the full capabilities of the Internet can begin with out
basic e-mail service or with Juno Gold, then migrate to Juno Web once they are
ready to do so."
<PAGE>
Gatefold:
 
[JUNO Online Services]
 
The picture on these pages depicts a Juno user's inbox as it appears on that
user's computer screen. Across the top of the screen is an ad banner for Qwest,
as well as three icons representing three features of Juno Online Services:
Read, Write and Web. The numbered sidebar text points to each of the icons, and
reads:
 
"[1]
Click to read.
Read and organize your incoming e-mail on Juno's "Read" screen."
 
"[2]
Click to write.
Send messages to anyone with an Internet e-mail address -- along with pictures
and more, if you are a Juno Gold or Juno Web subscriber."
 
"[3]
Click to go to the Web.
As a Juno Web subscriber, you can click here to connect to the Web, starting
each session at Juno's "portal" site.
 
Below the ad banner and icons is the Juno user's inbox, which lists various
e-mail messages received, and below that list is the text of an e-mail message
to the Juno user, including two attachments.
 
Below and to the right of the picture of the computer screen is text that reads:
 
"Above: Version 2.0 of Juno's software."
 
To the right of the screen picture is a depiction of the Juno home page,
entitled "Juno Web," including a search window, as well as various hyperlinks to
other spots on the Juno Web site. The caption below it reads:
 
"home.juno.com
When Juno Web subscribers begin a Web session, the first pages they see provide
them with a broad set of tools and content to help them understand, navigate,
and use the Web."
 
                                                                     [Juno Logo]
<PAGE>
    YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS. JUNO
ONLINE SERVICES HAS NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH DIFFERENT
INFORMATION. JUNO ONLINE SERVICES IS NOT MAKING AN OFFER OF THESE SECURITIES IN
ANY STATE WHERE THE OFFER IS NOT PERMITTED. YOU SHOULD NOT ASSUME THAT THE
INFORMATION PROVIDED BY THIS PROSPECTUS IS ACCURATE AS OF ANY DATE OTHER THAN
THE DATE ON THE FRONT OF THIS PROSPECTUS.
 
                            ------------------------
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                            ---------
<S>                                                                                                         <C>
Prospectus Summary........................................................................................          4
Risk Factors..............................................................................................          9
Forward-Looking Statements................................................................................         25
Use of Proceeds...........................................................................................         26
Dividend Policy...........................................................................................         26
Capitalization............................................................................................         27
Dilution..................................................................................................         28
Selected Consolidated Financial Data......................................................................         29
Management's Discussion and Analysis of Financial Condition and Results of Operations.....................         31
Business..................................................................................................         49
Management................................................................................................         62
Certain Transactions......................................................................................         73
Principal Stockholders....................................................................................         76
Description of Capital Stock..............................................................................         78
Shares Eligible for Future Sale...........................................................................         82
United States Tax Consequences to Non-United States Holders...............................................         84
Underwriting..............................................................................................         87
Legal Matters.............................................................................................         90
Experts...................................................................................................         90
Where You Can Find Additional Information.................................................................         90
Index to Consolidated Financial Statements................................................................        F-1
</TABLE>
 
                            ------------------------
 
    Until       , 1999 (25 days after the date of this prospectus), all dealers
that buy, sell or trade the common stock, whether or not participating in this
offering, may be required to deliver a prospectus. This is in addition to the
dealers' obligation to deliver a prospectus when acting as underwriters and with
respect to their unsold allotments or subscriptions.
 
                                       3
<PAGE>
                               PROSPECTUS SUMMARY
 
    BECAUSE THIS IS ONLY A SUMMARY, IT DOES NOT CONTAIN ALL OF THE INFORMATION
THAT MAY BE IMPORTANT TO YOU. YOU SHOULD READ THE ENTIRE PROSPECTUS, INCLUDING
"RISK FACTORS" AND THE CONSOLIDATED FINANCIAL STATEMENTS AND THE NOTES THERETO,
BEFORE DECIDING TO INVEST IN OUR COMMON STOCK.
 
                                  OUR COMPANY
 
    Juno Online Services, Inc. is a leading provider of Internet-related
services to millions of computer users throughout the United States. We offer
several levels of service, ranging from basic dial-up Internet e-mail--which is
provided to the end user for free--to full, competitively priced access to the
World Wide Web. Our strategy of offering several different service levels and
our easy-to-use, intuitive software are designed to attract a broad spectrum of
users, including those who are interested only in e-mail, those who initially
begin with e-mail but over time develop a need for Web access, and those who
seek full Web access from the outset.
 
    Our services are provided nationwide through over 1,900 local telephone
numbers, which we lease from several providers. These phone numbers can be
reached by the vast majority of the U.S. population without having to place a
long distance telephone call. Our revenues are derived primarily from the
subscription fees we charge for the use of our more advanced service levels,
from the sale of advertising, and from the direct sale of products to our
subscribers.
 
    From the time of our inception, we have pursued a two-phase business
strategy. During the first phase, we focused on building computer systems and
related infrastructure that could be rapidly expanded to accommodate increasing
numbers of users and on maximizing the number of subscribers to our free basic
e-mail service. We believed that offering this service for free would allow us
to rapidly and cost-effectively build a large user base from which we might
ultimately expect to derive various forms of revenue. We planned to draw on our
ability to communicate inexpensively with our user base in order to display
advertising and market products to our subscribers. We believed the economics of
these activities would be enhanced by technology we had developed that allowed
us to take advantage of a substantial number of hours of customer contact while
paying for a much smaller number of hours during which customers were actually
connected by telephone to our central computers. In addition, we planned to
offer our basic e-mail users the opportunity to purchase more advanced services
including full Web access for which we would charge subscription fees. We
believed that our basic e-mail users would be more likely to purchase these
advanced services from us than from a competing service provider due to their
expected reluctance to switch e-mail addresses.
 
    In July 1998, we commenced the second phase of our business strategy by
introducing two additional service levels, for which we receive subscription
fees. JUNO GOLD supplements our basic e-mail service by allowing users to send
and receive non-text files such as pictures, spreadsheets, and word processor
documents. JUNO WEB provides full Internet access using either of the two most
popular Web browsers.
 
    More than 6.8 million Juno accounts have been created since the launch of
our basic e-mail service in April 1996. During the month of March 1999, an
average of 912,000 user accounts dialed into our service on any given day, with
a total of 2.4 million user accounts connecting during the full month of March,
and 3.1 million during the three-month period ending March 31, 1999. We launched
Juno Gold and Juno Web, our billable subscription services, on July 22, 1998,
and as of March 31, 1999, we had approximately 207,000 subscribers to these
services, consisting of approximately 86,000 subscribers to Juno Gold and
approximately 121,000 to Juno Web. We have initially marketed Juno Gold and Juno
Web only to our own free e-mail subscribers. We intend, however, to begin
marketing these services beyond the existing Juno user base through a
substantial external marketing campaign beginning in the second quarter of 1999.
 
                                       4
<PAGE>
   
    As of March 31, 1999, approximately 200 firms had advertised on the Juno
services. We have also entered into a number of major strategic marketing
alliances, including several that involve multi-million-dollar guaranteed
minimum payments to Juno. Our strategic marketing alliances include multi-year
agreements with First USA, Qwest, and The Hartford, as well as a one-year
agreement with AT&T Wireless Services. These advertising and strategic marketing
activities benefit from our ability to target advertising to selected segments
of the Juno subscriber base on the basis of a wide variety of information
obtained from a detailed electronic questionnaire that must be completed in
order to sign up for Juno's basic e-mail service.
    
 
                               MARKET OPPORTUNITY
 
    The Internet is becoming an increasingly significant global medium for
communications, advertising, and commerce. International Data Corporation
estimates that more than 56 million individuals in the United States used the
Internet in 1998, and projects that this figure will reach 136 million by the
year 2002. IDC also projects that consumer-targeted dial-up Internet access
revenues in the U.S. will grow from $4.7 billion in 1998 to $10.6 billion in
2002. In addition, Jupiter Communications has projected that online advertising
expenditures will grow from an estimated $1.9 billion in 1998 to $7.7 billion in
2002.
 
                                  OUR STRATEGY
 
    We seek to strengthen our position as a leading provider of consumer
Internet-related services. In particular, we plan to:
 
    - Rapidly expand our overall subscriber base
 
    - Migrate subscribers to higher levels of service
 
    - Leverage and expand our strategic marketing alliances and advertising
      sales
 
    - Embrace new technologies while maintaining technology independence
 
                              RECENT DEVELOPMENTS
 
    In March 1999, Juno completed a private placement of redeemable convertible
preferred stock with a group of investors including Intel Corporation, News
Corporation, Prospect Street Ventures and Sycamore Ventures. We received net
proceeds of $61.8 million from this private placement. See "Management's
Discussion and Analysis of Financial Condition and Results of
Operations--Liquidity and Capital Resources."
 
                                       5
<PAGE>
                                  THE OFFERING
 
   
    The following information excludes 3,241,480 shares of common stock issuable
upon the exercise of stock options outstanding as of May 5, 1999, with a
weighted average exercise price of $4.27 per share.
    
 
   
<TABLE>
<S>                                   <C>
Common Stock Offered................  6,500,000 shares
 
Common Stock Outstanding
  After this Offering...............  34,584,566 shares
 
Use of Proceeds.....................  We intend to use the net proceeds of this offering
                                      for subscriber acquisition, advertising, brand
                                      marketing, continued investment in the development of
                                      our Internet services, enhancements of our network
                                      infrastructure, repayment of approximately $8.8
                                      million of debt to an affiliated entity and other
                                      general corporate purposes. We may also use a portion
                                      of the proceeds for acquisitions, strategic
                                      alliances, or joint ventures. See "Use of Proceeds."
 
Proposed Nasdaq National Market
  Symbol............................  "JWEB"
</TABLE>
    
 
                            ------------------------
 
    "Juno Web" and "Juno Gold" are trademarks, and "Juno" and Juno Online
Services, Inc.'s logo are registered trademarks, of Juno Online Services, Inc.
Each trademark, trade name or service mark of any other company appearing in
this prospectus belongs to its holder.
 
    Juno Online Services, Inc. was incorporated in Delaware on July 2, 1996 and
is the successor by merger to Juno Online Services, L.P., which was formed on
June 30, 1995 as a Delaware limited partnership. Our principal executive offices
are located at 1540 Broadway, New York, New York 10036. Our telephone number at
that location is (212) 597-9000. INFORMATION CONTAINED ON OUR WEB SITES DOES NOT
CONSTITUTE PART OF THIS PROSPECTUS. References in this prospectus to "Juno,"
"we," "our," and "us" refer to Juno Online Services, Inc., a Delaware
corporation, and its predecessor prior to the merger, Juno Online Services,
L.P., a Delaware limited partnership.
 
                            ------------------------
 
    UNLESS OTHERWISE INDICATED, ALL INFORMATION IN THIS PROSPECTUS:
 
    - REFLECTS THE STATUTORY MERGER OF JUNO ONLINE SERVICES, L.P. WITH AND INTO
      JUNO ONLINE SERVICES, INC. ON MARCH 1, 1999;
 
    - REFLECTS A 1 FOR 4.5 REVERSE STOCK SPLIT OF EACH CLASS OF OUR CAPITAL
      STOCK TO BE EFFECTED PRIOR TO THE CLOSING OF THIS OFFERING;
 
    - REFLECTS THE AUTOMATIC CONVERSION OF ALL SHARES OF REDEEMABLE CONVERTIBLE
      PREFERRED STOCK INTO 27,822,751 SHARES OF OUR COMMON STOCK UPON THE
      CLOSING OF THIS OFFERING; AND
 
    - ASSUMES NO EXERCISE OF THE UNDERWRITERS' OVER-ALLOTMENT OPTION.
 
                                       6
<PAGE>
               SUMMARY CONSOLIDATED FINANCIAL AND OPERATING DATA
 
    The following table sets forth summary consolidated financial and operating
data for Juno. You should read this information together with the consolidated
financial statements and the notes to those statements appearing elsewhere in
this prospectus. See "Selected Consolidated Financial Data" and "Management's
Discussion and Analysis of Financial Condition and Results of Operations."
 
   
<TABLE>
<CAPTION>
                                      PERIOD FROM
                                       INCEPTION
                                       (JUNE 30,                                             THREE MONTHS
                                        1995) TO         YEAR ENDED DECEMBER 31,           ENDED MARCH 31,
                                      DECEMBER 31,  ----------------------------------  ----------------------
                                          1995         1996        1997        1998        1998        1999
                                      ------------  ----------  ----------  ----------  ----------  ----------
                                                       (IN THOUSANDS, EXCEPT PER SHARE DATA) (UNAUDITED)
<S>                                   <C>           <C>         <C>         <C>         <C>         <C>
STATEMENT OF OPERATIONS DATA:
  Revenues:
    Billable services...............   $       --   $        6  $    1,371  $    6,645  $      465  $    5,806
    Advertising and transaction
      fees..........................           --          127       1,875       6,454       1,228       2,265
    Direct product sales............           --            3       5,845       8,595       2,577       1,649
                                      ------------  ----------  ----------  ----------  ----------  ----------
      Total revenues................           --          136       9,091      21,694       4,270       9,720
                                      ------------  ----------  ----------  ----------  ----------  ----------
  Cost of revenues:
    Billable services...............           --           --       1,053       5,606         387       4,678
    Advertising and transaction
      fees..........................           --          278       1,659       3,725         825       1,080
    Direct product sales............           --            3       5,796       7,627       2,426       1,424
                                      ------------  ----------  ----------  ----------  ----------  ----------
      Total cost of revenues........           --          281       8,508      16,958       3,638       7,182
                                      ------------  ----------  ----------  ----------  ----------  ----------
  Operating expenses:
    Operations, free service........           --        5,803      11,075       9,383       2,824       1,846
    Subscriber acquisition..........          592        6,993       3,140       5,334       1,453       2,700
    Sales and marketing.............          389        4,276      12,593      11,584       4,270       2,312
    Product development.............        2,577        3,741       4,860       7,345       1,835       1,854
    General and administrative......          275        2,172       2,897       2,760         914         704
                                      ------------  ----------  ----------  ----------  ----------  ----------
      Total operating expenses......        3,833       22,985      34,565      36,406      11,296       9,416
                                      ------------  ----------  ----------  ----------  ----------  ----------
      Loss from operations..........       (3,833)     (23,130)    (33,982)    (31,670)    (10,664)     (6,878)
  Interest income, net..............           --          128         243          44          74         111
                                      ------------  ----------  ----------  ----------  ----------  ----------
      Net loss......................   $   (3,833)  $  (23,002) $  (33,739) $  (31,626) $  (10,590) $   (6,767)
                                      ------------  ----------  ----------  ----------  ----------  ----------
                                      ------------  ----------  ----------  ----------  ----------  ----------
 
  Pro forma basic and diluted net
    loss per share (1)..............                                        $    (1.85)             $    (0.32)
                                                                            ----------              ----------
                                                                            ----------              ----------
  Weighted average shares
    outstanding used in pro forma
    basic and diluted per share
    calculation (1).................                                            17,091                  21,225
                                                                            ----------              ----------
                                                                            ----------              ----------
</TABLE>
    
<TABLE>
<CAPTION>
                                                        DECEMBER 31,                          MARCH 31,
                                      ------------------------------------------------  ----------------------
<S>                                   <C>           <C>         <C>         <C>         <C>         <C>
                                          1995         1996        1997        1998        1998        1999
                                      ------------  ----------  ----------  ----------  ----------  ----------
 
<CAPTION>
                                                             (IN THOUSANDS)
<S>                                   <C>           <C>         <C>         <C>         <C>         <C>
SELECTED SUBSCRIBER DATA:
  Total subscriber accounts as of
    (2).............................           --        1,042       3,887       6,336       4,699       6,817
    Subscriber accounts that
      connected in the three-month
      period ended..................           --        1,002       2,512       3,108       2,924       3,108
    Subscriber accounts that
      connected in the month
      ended.........................           --          823       1,986       2,434       2,340       2,438
    Average subscriber accounts that
      connected per day in the month
      ended.........................           --          280         644         887         889         912
  Billable subscription service
    accounts as of (3)..............           --           --          --         144          --         207
</TABLE>
 
                                       7
<PAGE>
<TABLE>
<CAPTION>
                                                                                               MARCH 31, 1999
                                                                                          -------------------------
<S>                                                                                       <C>        <C>
                                                                                           ACTUAL    AS ADJUSTED(4)
                                                                                          ---------  --------------
 
<CAPTION>
                                                                                                 (UNAUDITED)
                                                                                               (IN THOUSANDS)
<S>                                                                                       <C>        <C>
BALANCE SHEET DATA:
  Cash and cash equivalents.............................................................  $  53,165    $  115,893
  Working capital.......................................................................     48,000       112,288
  Total assets..........................................................................     71,660       134,388
  Total indebtedness, including current maturities......................................      9,930         1,118
  Redeemable convertible preferred stock................................................    141,431            --
  Total stockholders' equity (deficit)..................................................    (98,829)      114,142
</TABLE>
 
- ------------------------
 
   
(1) Gives pro forma effect to the following:
    
 
   
    - treatment of Class A limited partnership units as common stock for all
      periods presented; and
    
 
   
    - conversion of Series B redeemable convertible preferred stock for the
      period following the March 1999 statutory merger.
    
 
    See the consolidated financial statements and the notes to these statements
    appearing elsewhere in this prospectus for the determination of the number
    of shares used in computing pro forma basic and diluted loss per share.
 
(2) Includes all user accounts created since Juno's inception, regardless of
    activity level, if any, net of accounts that have been cancelled.
 
(3) Billable subscription service accounts are a subset of total subscriber
    accounts and, to the extent applicable, are also included in the number of
    subscriber accounts shown as having connected during the periods described.
 
   
(4) As adjusted to reflect the following:
    
 
   
    - the sale of 6,500,000 shares of common stock offered hereby at an assumed
      initial public offering price of $12.00 per share after deducting the
      estimated underwriting discount and estimated offering expenses payable by
      Juno;
    
 
   
    - the repayment of approximately $8.8 million of debt; and
    
 
    - the automatic conversion of all outstanding shares of redeemable
      convertible preferred stock into 27,822,751 shares of common stock upon
      the closing of this offering.
 
    See "Use of Proceeds" and "Capitalization."
 
                                       8
<PAGE>
                                  RISK FACTORS
 
    YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED BELOW BEFORE MAKING AN
INVESTMENT DECISION. IF ANY OF THE FOLLOWING RISKS ACTUALLY OCCUR, OUR BUSINESS
AND FINANCIAL RESULTS MAY SUFFER. IN THAT CASE, THE TRADING PRICE OF OUR COMMON
STOCK COULD DECLINE AND YOU COULD LOSE ALL OR PART OF YOUR INVESTMENT.
 
BECAUSE WE HAVE OFFERED OUR BASIC E-MAIL SERVICE FOR ONLY THREE YEARS AND OUR
  BILLABLE SUBSCRIPTION SERVICES FOR LESS THAN ONE YEAR, THERE IS LIMITED
  INFORMATION UPON WHICH YOU CAN EVALUATE OUR BUSINESS
 
    We have a limited operating history upon which you can evaluate our business
and our services. We began offering our free basic e-mail service to the public
in April 1996 and first offered our initial billable subscription services to
the public in July 1998. As a company in the new and rapidly evolving market for
Internet services, we face numerous risks and uncertainties. Some of these risks
relate to our ability to:
 
    - attract and retain subscribers to our free basic e-mail service and to
      Juno Gold and Juno Web, our billable subscription services;
 
    - anticipate and adapt to the changing Internet market;
 
    - generate advertising revenues and direct product sales;
 
    - maintain and develop strategic relationships with business partners to
      market their products over our services;
 
    - implement an effective marketing strategy to promote awareness of the Juno
      services;
 
    - respond to actions taken by our competitors;
 
    - develop and deploy successive versions of the Juno software necessary to
      use our services;
 
    - operate computer systems and related infrastructure adequate to
      effectively manage our growth and provide our basic e-mail service and our
      billable subscription services;
 
    - manage the billing systems used to invoice subscribers to Juno Gold and
      Juno Web; and
 
    - attract, retain and motivate qualified personnel.
 
    Our business and financial results will depend heavily on the commercial
acceptance and profitability of our billable subscription services. If we are
unsuccessful in addressing these risks or in executing our business strategy,
our business and financial results may suffer. Please see "Management's
Discussion and Analysis of Financial Condition and Results of Operations" for
detailed information on our limited operating history.
 
WE HAVE A HISTORY OF LOSSES SINCE OUR INCEPTION IN 1995 AND EXPECT CONTINUED
  LOSSES FOR THE FORESEEABLE FUTURE
 
    Since our inception in 1995, we have not been profitable. We have incurred
substantial costs to create and introduce our various services, to operate these
services, to promote awareness of these services and to grow our business. We
incurred net losses of approximately $3.8 million from inception through
December 31, 1995, $23.0 million for the year ended December 31, 1996, $33.7
million for the year ended December 31, 1997, $31.6 million for the year ended
December 31, 1998 and $6.8 million for the three months ended March 31, 1999. As
of March 31, 1999, our accumulated net losses totaled $99.0 million. We incurred
negative cash flows from operations of approximately $16.4 million for the year
ended December 31, 1996, $33.6 million for the year ended December 31, 1997 and
$20.9 million for the year ended December 31, 1998. For the three months ended
March 31, 1999, we used $6.2 million in cash for working capital purposes and to
fund losses from operations. In addition, we paid $10.0 million for advertising
that may be used at any time prior to March 2001, bringing total net cash used
in operating activities to $16.2 million.
 
                                       9
<PAGE>
    Since we operated as a limited partnership prior to the merger of Juno
Online Services, L.P. into Juno Online Services, Inc. in March 1999, taxable
losses incurred prior to the merger were allocated to the partners of Juno
Online Services, L.P. for reporting on their income tax returns. As a result, we
will not be able to offset future taxable income, if any, against losses
incurred prior to the merger.
 
    We expect operating losses and negative cash flows to continue for the
foreseeable future as we continue to incur significant expenses. We cannot
assure you that we will ever be successful in implementing our business
strategies or in addressing the risks and uncertainties facing our company. Even
if we do address these risks successfully, we may not be profitable in the
future. Were we to achieve profitability, we cannot assure you that we would be
able to sustain or increase profitability on a quarterly or annual basis in the
future. Please see "Selected Consolidated Financial Data" and "Management's
Discussion and Analysis of Financial Condition and Results of Operations" for
more detailed information.
 
JUNO'S BUSINESS IS SUBJECT TO FLUCTUATIONS IN OPERATING RESULTS WHICH MAY
  NEGATIVELY IMPACT THE PRICE OF OUR STOCK
 
    Our revenues, expenses and operating results have varied in the past and may
fluctuate significantly in the future due to a variety of factors, many of which
are outside of our control. These factors include, among others:
 
    - the rate of new subscriber acquisitions and seasonal trends relating to
      subscriber usage of our services;
 
    - the timing and effectiveness of our marketing efforts to acquire
      subscribers and promote the Juno brand;
 
    - the timing and effectiveness of any revenue sharing arrangements or other
      strategic alliances into which we enter;
 
    - the demand for Internet advertising and seasonal trends relating to
      Internet advertising spending;
 
    - seasonal trends relating to the demand for products sold over the
      Internet;
 
    - capital expenses related to upgrading our computer systems and related
      infrastructure;
 
    - our ability to protect our systems from any telecommunications failures,
      power loss, or software-related system failures;
 
    - our ability to integrate operations and technologies from any acquisitions
      or other business combinations or relationships into which we enter;
 
    - the extent to which we experience increased competition in the markets for
      Internet services, Internet advertising and direct product sales;
 
    - changes in operating expenses including, in particular, telecommunications
      expenses and the cost of providing various types of technical and
      non-technical customer support to our subscribers; and
 
    - economic conditions specific to the Internet as well as general economic
      and market conditions.
 
    Since we expect to be heavily dependent on revenues from our billable
subscription services in the foreseeable future, our revenues are likely to be
particularly affected by our ability to recruit new subscribers directly for our
billable subscription services, upgrade users of our free basic e-mail service
to our billable subscription services, and retain subscribers to our billable
subscription services. In addition, our operating expenses are based on our
expectations of our future revenues and are relatively fixed in the short term.
We may be unable to adjust spending quickly enough to offset any unexpected
revenue shortfall, which may cause our business and financial results to suffer.
 
                                       10
<PAGE>
    Due to all of the foregoing factors and the other risks discussed in this
section, you should not rely on quarter-to-quarter comparisons of our results of
operations as an indication of future performance. It is possible that in some
future periods our results of operations may be below the expectations of public
market analysts and investors. In this event, the price of our common stock is
likely to fall. Please see "Management's Discussion and Analysis of Financial
Condition and Results of Operations" for detailed information on our operating
results.
 
OUR BUSINESS MAY SUFFER IF WE HAVE DIFFICULTY ACQUIRING SUBSCRIBERS TO OUR FREE
  BASIC E-MAIL SERVICE, JUNO GOLD OR JUNO WEB
 
    We may not succeed in acquiring a sufficiently large subscriber base for our
free basic e-mail service and our billable subscription services, or in
persuading a significant number of our free basic e-mail subscribers to upgrade
to Juno Gold and Juno Web.
 
    To acquire new members, we currently rely on multiple distribution channels
for our free proprietary software that enables subscribers to use our services.
Our ability to recruit new subscribers may depend on our ability to enter into
additional distribution agreements and to retain our current distribution
partners. We cannot be sure that we will be able to enter into additional, or
maintain or replace our current, distribution agreements on favorable terms, or
that any of our distribution partners will be able to market our services
effectively. Many of our distribution partners also distribute competing
products, and are free to terminate our distribution arrangements at their
convenience. Our inability to recruit, manage or retain distribution partners,
or the inability of these distribution partners to effectively promote and
distribute our software, may cause our business and financial results to suffer.
 
    Our business strategy contemplates that a significant percentage of the
subscribers to our free basic e-mail service will decide over time to upgrade to
Juno Gold and Juno Web. We are relying on this migration as a major source of
subscribers to these billable subscription services and, since July 1998, we
have conducted advertising to our free e-mail subscribers to encourage them to
upgrade. Over time, repeated exposure to these advertisements may cause their
effectiveness to decline. As a result, we expect that we will need to rely on
more expensive forms of external marketing and promotion to attract additional
users directly to our billable subscription services, as well as to attract new
users to our free basic e-mail service. If our marketing techniques fail to
generate the anticipated conversion rate from free to billable subscription
services, if the acquisition cost for subscribers acquired directly into our
billable subscription services is greater than expected, or if technical
limitations make the conversion process more difficult or time-consuming than
anticipated, our business and financial results may suffer. Please see "--Our
marketing program may not succeed in generating new subscribers or in persuading
subscribers to upgrade to Juno Gold or Juno Web" for more information on our
marketing activities.
 
OUR BUSINESS MAY SUFFER IF WE HAVE DIFFICULTY RETAINING SUBSCRIBERS TO OUR FREE
  BASIC E-MAIL SERVICE, JUNO GOLD OR JUNO WEB
 
    Our business and financial results are also dependent on our ability to
retain subscribers to our services. Each month, a significant number of
subscribers to our billable subscription services choose to cancel the service.
In addition, a significant number of subscribers to our free basic e-mail
service become inactive each month. As a result, the total number of subscribers
using our free basic e-mail service in a given month has remained substantially
the same over the last six months, even though we have added new subscribers
during that period. We believe that intense competition has caused, and may
continue to cause, some of our subscribers to switch to other services. It is
relatively easy for Internet users to switch to competing providers and we
cannot be certain that any steps we take will maintain or improve subscriber
retention. In addition, some new subscribers may decide to use our services out
of curiosity regarding the Internet, or to take advantage of low-cost
introductory offers for Juno Gold and Juno Web, and may later discontinue using
our services. Furthermore, we may in the
 
                                       11
<PAGE>
future charge a fee for our basic e-mail service or limit the amount a
subscriber may use this service in a given period. In the event we were to
implement these kinds of charges and/or restrictions, we may lose a significant
number of our basic e-mail subscribers. If we are unable to retain subscribers
to both our basic e-mail service and our billable subscription services, or if
we experience an increase in the rate of cancellations by subscribers to our
billable subscription services, our business and financial results may suffer.
Please see "--Competition in the markets for Internet services, Internet
advertising and direct product sales is likely to increase in the future and may
harm our business" for more information concerning the competition facing our
business.
 
OUR MARKETING PROGRAM MAY NOT SUCCEED IN GENERATING NEW SUBSCRIBERS OR IN
  PERSUADING SUBSCRIBERS TO UPGRADE TO JUNO GOLD OR JUNO WEB
 
    We expect to use a significant portion of the proceeds from this offering
for an extensive marketing campaign. This campaign will be directed at
encouraging users to sign up directly for our billable subscription services and
persuading users of our free basic e-mail service to upgrade to our billable
subscription services. This marketing program may include forms of advertising,
such as television and radio advertising, with which we have limited experience.
There are risks that this campaign may not be effective in accomplishing one or
both of these goals. In addition, it is possible that, over time, it will become
more difficult and expensive to effectively market Juno Gold and Juno Web to
users of our free basic e-mail service and that the rate at which users of the
free basic e-mail service upgrade to our billable subscription services will
decline. We also do not know what kind of advertising our competitors will
undertake, the timing and extent of advertising by our competitors, or whether
this will impact our marketing plans or expenses. If we incur significant costs
in implementing our marketing program without generating sufficient new
subscribers to our services, our business and financial results will suffer.
 
COMPETITION IN THE MARKETS FOR INTERNET SERVICES, INTERNET ADVERTISING AND
  DIRECT PRODUCT SALES IS LIKELY TO INCREASE IN THE FUTURE AND MAY HARM OUR
  BUSINESS
 
    The market for Internet services is extremely competitive and includes a
number of substantial participants, including America Online, Microsoft and
AT&T. The markets for Internet-based advertising and direct product sales are
also very competitive.
 
    INTENSE COMPETITION EXISTS IN THE MARKET FOR INTERNET SERVICES
 
    We may not be able to compete successfully against current or future
competitors, and the competitive pressures that we face may cause our business
and financial results to suffer. We believe that the primary competitive factors
determining success in these markets include a reputation for reliability and
service, effective customer support, pricing, easy-to-use software and
geographic coverage. Other important factors include the timing and introduction
of new products and services and industry and general economic trends. Our
ability to compete depends upon many factors, many of which are outside of our
control. We expect this competition to continue to increase because the markets
in which we operate face few substantial barriers to entry. Competition may also
intensify as a result of industry consolidation and the ability of some of our
competitors to bundle Internet services with other products and services. Our
current and potential competitors include many large national companies that
have substantially greater market presence and financial, technical,
distribution, marketing and other resources than we have. This may allow them to
devote greater resources than we can to the development, promotion and
distribution and sale of products and services.
 
    In recruiting subscribers for our billable subscription services, we
currently compete, or expect to compete, with the following types of companies,
among others:
 
    - Established online service providers such as America Online, CompuServe,
      and The Microsoft Network;
 
                                       12
<PAGE>
    - Independent national Internet service providers such as EarthLink,
      MindSpring, and Prodigy;
 
    - Numerous independent regional and local Internet service providers which
      may offer lower prices than a national Internet service provider;
 
    - Various national and local telephone companies such as AT&T, MCI WorldCom
      and Pacific Bell; and
 
    - Companies providing Internet access through "set-top boxes" connected to a
      user's television, such as WebTV, or through a "cable modem" connected to
      a user's personal computer, such as @Home.
 
    In addition, Microsoft and Netscape, publishers of the Web browsers utilized
by most Internet users, including subscribers to Juno Web, each own or are owned
by online or Internet service providers that compete with Juno Web.
 
    In providing e-mail-related services, we compete with Web-based e-mail
services such as Microsoft's Hotmail and USA.net's Net@ddress.
 
    In addition, we do not currently compete internationally. If the ability to
provide Internet services internationally becomes a competitive advantage in our
markets and we do not begin to provide services internationally, we will be at a
disadvantage relative to our competitors.
 
    WE RELY ON REVENUES FROM ADVERTISING AND DIRECT PRODUCT SALES
 
    With respect to the generation of advertising revenue, we compete with many
of the market participants listed above as well as with various
advertising-supported Web sites, including "portal" sites such as Yahoo! and
Excite, "content" sites such as CNET and CNN.com, and interactive advertising
networks and agencies such as DoubleClick and 24/7 Media. We also compete with
traditional media such as print and television for a share of advertisers' total
advertising budgets. If advertisers perceive the Internet to be a limited or
ineffective advertising medium or perceive us to be less effective or less
desirable than other Internet advertising vehicles, advertisers may be reluctant
to advertise on our services. In selling products directly to our subscribers,
we compete with other Internet-based sellers as well as with stores and other
companies that do not distribute their products through the Internet. Many of
these competitors are larger than we are, enjoy greater economies of scale than
are available to us, have substantially greater resources than we have, and may
be able to offer more products or more attractive prices than we can. We believe
that this competition is likely to increase in the future. Please see "--Our
business may be adversely affected if the market for Internet advertising fails
to develop" and "--We rely on a single external marketing partner to fulfill
most of our direct product sales" for more information regarding our advertising
and direct products sales activities.
 
    OUR COMPETITION IS LIKELY TO INCREASE IN THE FUTURE
 
    Our competition is likely to increase. We believe this will probably happen
as Internet service providers and online service providers consolidate and
become larger, more competitive companies, and as large diversified
telecommunications and media companies acquire Internet service providers. The
larger Internet service providers and online service providers, including
America Online, offer their subscribers services such as instant messaging,
community message boards, and personal Web page hosting that we do not currently
provide. Some diversified telecommunications and media companies, such as AT&T,
have begun to bundle other services and products with Internet access services,
potentially placing us at a significant competitive disadvantage. These
competitors may be able to charge less than we do for Internet services, causing
us to reduce, or preventing us from raising, fees for our billable subscription
services. The ability of our competitors to enter into strategic alliances or
joint ventures could also put us at a serious competitive disadvantage.
Competition could require us to increase our spending for sales and marketing as
well as for subscriber acquisition in order to maintain our position in the
marketplace, and could also result in increased subscriber attrition. Any of
these
 
                                       13
<PAGE>
scenarios could harm our business and financial results, and we may not have the
resources to continue to compete successfully.
 
WE ARE DEPENDENT ON STRATEGIC MARKETING ALLIANCES AS A SOURCE OF REVENUES AND
  OUR BUSINESS COULD SUFFER IF ANY OF THESE ALLIANCES ARE TERMINATED
 
   
    Most of our strategic marketing partners have the right to terminate their
agreements with us on short notice. In February 1999, Bank of America notified
us of the termination of its agreement with us concerning the marketing of
credit cards to our subscribers, effective May 1, 1999. We have strategic
marketing alliances with a number of third parties, including AT&T Wireless,
Qwest, and The Hartford. We have also entered into a strategic marketing
alliance with First USA which became effective May 2, 1999. If any of our
strategic marketing agreements are terminated, we cannot assure you that we will
be able to replace the terminated agreement with an equally beneficial
arrangement. We also cannot assure you that we will be able to renew any of our
current agreements when they expire or, if we are, that we will be able to do so
on acceptable terms. We also do not know whether we will be successful in
entering into additional strategic marketing alliances, or that any additional
relationships, if entered into, will be on terms favorable to us. Our receipt of
revenues from our strategic marketing alliances may also be dependent on factors
which are beyond our control, such as the quality of the products or services
offered by our strategic marketing partners.
    
 
WE MUST ADAPT TO TECHNOLOGY TRENDS AND EVOLVING INDUSTRY STANDARDS OR WE WILL
  NOT BE COMPETITIVE
 
    Our failure to respond in a timely and effective manner to new and evolving
technologies, including cable modem and other broadband technology, could harm
our business and financial results. The Internet services market is
characterized by rapidly changing technology, evolving industry standards,
changes in member needs and frequent new service and product introductions. Our
business and financial results depend, in part, on our ability to use leading
technologies effectively, to develop our technical expertise, to enhance our
existing services and to develop new services that meet changing member needs on
a timely and cost-effective basis. In particular, we must provide subscribers
with the appropriate products, services and guidance required to best take
advantage of the rapidly evolving Internet. If the market for our billable
subscription services should fail to develop, develop more slowly than we
expect, become saturated with competitors, or develop in a fashion that renders
our services uncompetitive or otherwise unappealing to consumers, our business
and financial results may suffer.
 
    We are also at risk due to fundamental changes in the way that Internet
access may be provided in the future. Currently, consumers access Internet
services primarily through computers connected by telephone lines. Broadband
connections, however, allow significantly faster access to the Internet than is
possible using the telephone-based modems currently used by all of our
subscribers. The companies currently providing or expecting to begin providing
broadband connections to consumers' homes, including cable television companies,
local and long distance telephone companies, electric utility companies and
wireless communications companies, have decided or may decide to provide
Internet access as well. For example, competitors have developed technologies
that enable cable television operators to offer high-speed Internet access
through their cable facilities. These cable television operators, as well as
other competitors, may include Internet access in their basic bundle of services
or may offer Internet access for a nominal additional charge. Moreover, these
companies could prevent us in the future from delivering Internet access through
the wire and cable connections that they own, or from doing so on a
cost-effective basis. Even if we are not prevented from delivering our Internet
services through the broadband connections owned by others, we will likely need
to develop new technology or modify our services and the technology they use to
accommodate these developments. We may also have to modify the means by which we
deliver our Internet services, in which case we would incur significant costs.
If consumers adopt alternative forms of Internet access that provide a
continuous connection to the Internet rather than relying on a series of
separate dial-up connections, then any competitive advantage that we currently
realize because our technology minimizes connect
 
                                       14
<PAGE>
time may diminish. If other companies are able to prevent us from delivering our
Internet services through the wire and cable connections that they own, if we
are unable to adapt to the challenges posed by broadband technologies or if we
incur significant costs without generating sufficient revenues, our business and
financial results may suffer.
 
OUR BUSINESS MAY BE ADVERSELY AFFECTED IF THE MARKET FOR INTERNET ADVERTISING
  FAILS TO DEVELOP
 
    Our business and financial results are dependent on the use of the Internet
as an advertising medium. Internet-based advertising accounts for only a small
fraction of all advertising expenditures, and we cannot be sure that
Internet-based advertising will ever grow to account for a substantial
percentage of total advertising spending or when an increase might occur. Our
business may suffer if the market for Internet-based advertising fails to
develop or develops more slowly than expected. In addition, no standards have
been widely accepted to measure the effectiveness of Internet-based advertising.
If measurement standards do not develop, many advertisers may choose not to
advertise on the Internet. Different pricing models are used to sell
Internet-based advertising. Our revenues could suffer if we are unable to adapt
to new forms of, and new pricing models for, Internet-based advertising. It is
difficult to predict which, if any, forms of Internet-based advertising will
emerge as the industry standard. This makes it difficult to project our future
advertising rates and revenues. Moreover, "filter" software programs that limit
or prevent advertising from being delivered to an Internet user's computer are
available. Widespread adoption of this type of software could harm the
commercial viability of Internet-based advertising.
 
    Sales of advertising space on our services represents an important revenue
source for us. Competition for Internet-based advertising revenues is intense,
and this competition could result in significant price erosion over time. We
cannot assure you that we will be successful in selling advertising or capturing
a significant share of the market for Internet-based advertising. We also cannot
assure you that we will be able to sell advertising at the rates we currently
project. It is also possible that we will find it necessary to lower the rates
for advertising space on our services.
 
    We currently rely on our internal sales and marketing personnel for
generating sales leads and promoting our services to the advertising community.
In 1998, we closed some of the regional sales offices that we had previously
established. Since substantially all of our sales and marketing personnel are
now based in New York City, we may not be able to effectively market our
services to regional advertisers outside of New York. We also rely on the sales
and marketing personnel of Lycos, our Web site partner, for the sale of
advertising space on the default "portal" site used by Juno Web subscribers.
Although we have not done so in the past, we might also retain the services of
one or more external sales organizations to sell advertising space on our
network. We cannot be sure that our internal sales organization, Lycos or any
other independent sales organization will achieve our advertising sales
objectives in a cost-effective manner.
 
    If Internet-based advertising does not continue to grow, if we are unable to
capture a sufficient share of Internet-based advertising, or if Lycos or other
independent sales organizations do not perform as we anticipate, our business
and financial results may suffer.
 
OUR ADVERTISING SYSTEM REQUIRES LABOR AND IMPOSES COSTS ON US BEYOND THOSE
  ASSOCIATED WITH STANDARD WEB ADVERTISING
 
    Elements of advertising on Juno's services are non-standard when compared to
advertising on the Web and may put Juno at a competitive disadvantage. The
advertisements displayed on our services require customization that would not be
required by a Web site capable of displaying previously prepared standard
advertisements. This customization work increases the time necessary to prepare
an advertisement to be displayed on our services and the costs associated with
running these ads. We must also absorb the telecommunications cost associated
with initially downloading these ads to our subscribers, which is an expense
that advertising-supported Web sites do not incur. As ads become more complex,
our telecommunications expenses may increase. Furthermore, the costs associated
with
 
                                       15
<PAGE>
selling or attempting to sell advertising space on our services are significant.
These costs may be greater than the costs associated with selling advertising
space on Web sites that utilize standard Web advertising formats. Additionally,
our use of a proprietary advertising format could prevent us from packaging our
advertising space for sale by an advertising network such as DoubleClick. We
also rely on detailed data provided by our subscribers for purposes of targeting
some ads. We do not currently verify the accuracy of this data at the time it is
provided or require subscribers to update their information thereafter.
Furthermore, individuals who subscribe directly to one of our billable
subscription services are not currently required to provide this data. Any of
the above factors could discourage advertising on our network by some
advertisers.
 
SEASONAL TRENDS IN INTERNET USAGE AND ADVERTISING SALES MAY NEGATIVELY AFFECT
  OUR BUSINESS
 
    Seasonal trends are likely to affect the revenues we generate from operating
our Internet services. Subscribers typically use our Internet services less
during the summer months and year-end holiday periods. To the extent that our
revenues depend on the amount of usage by our subscribers, our revenues may be
lower during these periods. For example, some of the subscribers to Juno Web pay
us based on the number of hours they spend using our services in a given month.
In addition, the rate at which new subscribers sign up for our billable
subscription services, which were introduced in July 1998, may be lower during
the summer months and year-end holiday periods.
 
    We believe that advertising sales generally are lower in the first and third
calendar quarters of each year. We have recently seen this pattern reflected in
our results of operations and believe that this seasonal trend may continue.
 
    Since our operating expenses are based on our expectations of future
revenues, including seasonal fluctuations, it is possible that operating results
will suffer if these seasonal trends do not continue in the future or if
different seasonal trends develop in the future. Please see "Management's
Discussion and Analysis of Financial Condition and Results of Operations" for
more information on our operating results.
 
WE ARE DEPENDENT ON A SMALL NUMBER OF TELECOMMUNICATIONS CARRIERS AND MAY BE
  UNABLE TO FIND ADEQUATE REPLACEMENTS IF THEIR RATES INCREASE, SERVICE QUALITY
  DECLINES, OR IF THEY DISCONTINUE DOING BUSINESS WITH US
 
    Our business and financial results depend in significant part on the
capacity, affordability, reliability and security of our telephone company data
networks. To use our services, subscribers must initiate telephone connections
between their personal computers and computer hardware in local or regional
facilities known as "points of presence." We contract for the use of points of
presence around the country from various telecommunications carriers. These
carriers currently include UUNET Technologies and WorldCom Advanced Networks,
both of which are operated by MCI WorldCom; Concentric Network Corporation; and
Sprint Communications Company. These telecommunications companies also carry the
data between their points of presence and our central computers located in
Cambridge, Massachusetts and Jersey City, New Jersey.
 
    As of March 31, 1999, we had contracted for the use of over 1,900 local
telephone numbers associated with points of presence throughout the United
States. Some points of presence carry data both for our e-mail services and for
Juno Web, while others carry data only for our e-mail services or only for Juno
Web. The points of presence supporting Juno Web are not as broadly distributed
geographically as those supporting our e-mail services. As a result, a
significant minority of our subscriber base is unable to access Juno Web through
a point of presence that is within their local calling area. The inability of
some of our subscribers to easily upgrade to Juno Web or our inability to
recruit new members in some areas could harm our business. We cannot be sure if
or when additional infrastructure developments by our telecommunications
providers will result in points of presence that cover these areas.
 
                                       16
<PAGE>
    At various times in the past, network capacity constraints at particular
points of presence have prevented or delayed access by subscribers attempting to
connect to our services. This could happen in the future, especially during
times of peak usage. Difficulties accessing our services due to poor network
performance could cause our subscribers to terminate their membership with us.
Because we depend on third-party telecommunications carriers for crucial
portions of our network infrastructure, we do not have direct control over
network reliability and some aspects of service quality. A natural disaster or
other unanticipated problem that affects the points of presence or the
telecommunications lines we use, or that affects the nation's telecommunications
network in general, could cause interruptions in our services.
 
    Only a small number of telecommunications companies can provide the network
services we require. This number has been reduced through consolidation in the
telecommunications industry, and there is a significant risk that further
consolidation could make us reliant on an even smaller number of providers.
Currently, we are particularly dependent on companies controlled by MCI
WorldCom, which provide more than 1,300 of the approximately 1,900 points of
presence for which we contract in the United States. Furthermore, MCI WorldCom
has recently announced that it will begin to offer consumer Internet access,
making it a direct competitor of ours. Our business could be harmed if we are
unable to maintain a favorable relationship with MCI WorldCom. We cannot assure
you that we would be able to replace the services provided to us by MCI WorldCom
were our relationship with them to be terminated.
 
    Our financial results are highly sensitive to variations in prices for the
telecommunications services described above. We cannot assure you that
telecommunications prices will decline, or that there will not be
telecommunications price increases due to factors beyond our control. Some of
our telecommunications carriers impose minimum connection charges. Our business
could be harmed if minimum connection charges increase or become more prevalent.
We cannot assure you that our telecommunications carriers will continue to
provide us access to their points of presence on adequate price terms, or that
alternative services will be available in the event that their quality of
service declines or that our relationship with any of our current carriers is
terminated.
 
    Most of the telecommunications services we purchase are provided to us under
short-term agreements that the providers can terminate or elect not to renew. As
a result, there is a significant risk that any or all of UUNET Technologies,
WorldCom Advanced Networks, Concentric or Sprint could end their relationship
with us. In addition, each of our telecommunications carriers provides network
access to some of our competitors, and could choose to grant those competitors
preferential network access, potentially limiting our members' ability to access
the Internet or connect to our central computers. Furthermore, each of our
telecommunications providers competes, or has announced an intention to compete,
with us in the market to provide consumer Internet access. If our
telecommunications service providers were to decrease the levels of service or
access provided to us, or if they were to terminate their relationships with us
for competitive or other reasons, our business and financial results would
suffer.
 
WE ARE DEPENDENT ON THIRD PARTIES FOR TECHNICAL AND CUSTOMER SERVICE SUPPORT AND
  OUR BUSINESS MAY SUFFER IF THEY ARE UNABLE TO PROVIDE THESE SERVICES OR CANNOT
  EXPAND TO MEET OUR NEEDS
 
    Our business and financial results depend, in part, on the availability of
live technical and customer service support, and of inbound telemarketing and
disk distribution services. Should our ability to provide these services be
hampered, our business may suffer. Although many Internet service providers have
developed internal customer service operations designed to meet these needs, we
have elected to outsource these functions to third-party vendors. We currently
use ClientLogic Corporation for technical and customer service support and Call
Center Services, Inc. for telemarketing and disk fulfillment functions. As a
result, we maintain only a small number of internal customer service personnel.
We are thus not equipped to provide the necessary range of customer service and
 
                                       17
<PAGE>
telemarketing services in the event that either of our existing external
providers becomes unable or unwilling to offer these services to us.
 
    Our most important relationship is with ClientLogic, which, at March 31,
1999, provided us with approximately 315 full-time or part-time employees at its
facilities to service our account. The availability of call-in technical support
and customer service is especially important to acquire and retain subscribers
to Juno Gold and Juno Web, and we rely almost entirely on ClientLogic to provide
this function. At times, our subscribers have experienced lengthy waiting
periods to reach representatives trained to provide the technical or customer
support they require. As our services grow, we will need significantly more
support personnel in order to maintain current levels of technical and customer
support. If we elect to offer customer service features that we do not currently
support, such as 24-hour live support, or to enhance the overall quality of our
customer support for competitive reasons, we will require even greater
resources. We may have significantly expanded customer service requirements in
the future and it could become necessary to identify supplemental or replacement
vendors for these services. Our agreement with ClientLogic converts to a
month-to-month contract on August 1, 2000, providing either party the right to
terminate the relationship at any time upon one month's notice. Prior to that
date, ClientLogic can terminate the contract without cause upon 90 days notice.
In addition, ClientLogic may terminate the contract upon 60 days notice at any
time after August 1, 1999 if we do not reach agreement with ClientLogic with
regard to modifications ClientLogic proposes to the pricing terms of the
contract within 60 days of the modifications being proposed. If our relationship
with ClientLogic terminates and we are unable to enter into a comparable
arrangement with a replacement vendor, if ClientLogic is unable to provide
enough personnel to provide the quality and quantity of service we desire, or if
system failures, outages or other technical problems make it difficult for our
subscribers to reach customer service representatives at ClientLogic, our
business and financial results may suffer.
 
WE RELY ON A SINGLE EXTERNAL MARKETING PARTNER TO FULFILL MOST OF OUR DIRECT
  PRODUCT SALES
 
    If we fail to manage our direct product sales efforts in a cost-effective
manner, or if we fail to maintain the relationship with our external marketing
partner, our business may suffer. We rely primarily on Direct Alliance
Corporation, a subsidiary of Insight Enterprises, for the procurement,
warehousing, fulfillment, billing and customer service aspects of our direct
product sales. Should our relationship with this vendor be disrupted, our
ability to engage in direct product sales will be severely curtailed. In the
past, a substantial portion of our revenue has come from the sale of products
directly to our subscribers. Our ability to sell products directly to our
subscribers is dependent in part upon:
 
    - the willingness of subscribers to overcome concerns regarding the security
      of online financial transactions;
 
    - our ability to select and profitably acquire and provide merchandise that
      is interesting to our subscriber base;
 
    - our ability to compete with established retail business and other online
      sellers; and
 
    - other factors that may be outside of our control.
 
In addition, if we were to experience unusually high rates of returns for the
products we sell to our subscribers or if we were unable to sell all the
products in our inventory, the net revenues we generate from our direct sales
activities would be harmed. In addition, our revenues may suffer if we face
increased competition in our direct product sales activities.
 
DISRUPTION OF OUR INTERNET SERVICES DUE TO SECURITY BREACHES AND SYSTEM FAILURES
  COULD RESULT IN SUBSCRIBER CANCELLATIONS
 
    Both our infrastructure and the infrastructure of our network providers are
vulnerable to security breaches or similar disruptive problems and system
failures. Our systems are also subject to telecommunications failures, power
loss, software-related system failures and various other events. Any
 
                                       18
<PAGE>
of these events, whether intentional or accidental, could lead to interruptions,
delays or cessation of service to our subscribers. This could cause some of our
subscribers to stop using our Internet services. Third parties could also
potentially jeopardize the security of confidential information stored in our
computer systems or our subscribers' computer systems through their
inappropriate use of the Internet, which could cause losses to us or our
subscribers or deter some people from subscribing to our services. People may be
able to circumvent our security measures or the security measures of our third
party network providers.
 
    We may have to interrupt, delay or cease service to our subscribers to
alleviate problems caused by computer viruses, security breaches or other
failures of network security. Any damage or failure that interrupts or delays
our operations could result in subscriber cancellations, could harm our
reputation, and could affect our business and financial results. In addition, we
expect that our subscribers will increasingly use the Internet for commercial
transactions in the future. Any network malfunction or security breach could
cause these transactions to be delayed, not completed at all or completed with
compromised security. Our subscribers or others may assert claims of liability
against us as a result of this type of failure. Furthermore, until more
comprehensive security technologies are developed, the security and privacy
concerns of existing and potential subscribers may inhibit the growth of the
Internet service industry in general and our subscriber base and revenue in
particular.
 
    Our insurance policies may not adequately compensate us for any losses that
may occur due to any failures in our systems or interruptions in our services.
 
RAPID GROWTH IN OUR BUSINESS COULD STRAIN OUR MANAGERIAL, OPERATIONAL,
  FINANCIAL, AND INFORMATION SYSTEMS RESOURCES
 
    The anticipated future growth necessary to expand our operations will place
a significant strain on our managerial, operational, financial and information
systems resources. If we are unable to manage our growth effectively, our
business and financial results will suffer. In order to achieve growth in
revenues from Internet advertising, we will need to expand our sales efforts and
continue to improve and develop our software. In order to achieve growth in
revenues from Juno Gold and Juno Web, we will need to expand our marketing
efforts, promote the Juno brand, expand the computer systems and related
infrastructure we use to provide our Internet services, and increase both our
internal and outsourced customer service capabilities. We expect that we will
need to continually improve our financial and managerial controls, billing
systems, reporting systems and procedures, and we will also need to continue to
expand, train and manage our workforce. We had 65 employees at December 31,
1996, 152 employees at December 31, 1997, 144 employees at December 31, 1998 and
147 employees at March 31, 1999. In addition, as of March 31, 1999, we also
retained the services of 47 individuals in India who are employed by an
affiliate of Juno. We have significantly increased our reliance on outsourced
support for customer service, technical, and back-office functions. We expect
the size of our own workforce and our reliance on outsourced services will
continue to increase for the foreseeable future.
 
    The demand on our network infrastructure, technical staff and technical
resources has grown rapidly with our expanding subscriber base. We cannot be
certain that our infrastructure, technical staff and technical resources will
adequately accommodate or facilitate the anticipated growth of our subscriber
base. In particular, if we were to experience repeated and/or prolonged
system-wide service outages, our business and financial results would suffer.
 
WE FACE POTENTIAL LIABILITY FOR INFORMATION TRANSMITTED OR RETRIEVED THROUGH OUR
  INTERNET SERVICES
 
    Our business and financial results may suffer if we incur liability as a
result of information transmitted or retrieved through our services. The
liability of Internet service providers and online services companies for
information transmitted or retrieved through their services is uncertain. It is
possible that claims may be filed against us based on a variety of theories,
including defamation, obscenity, negligence, copyright or trademark
infringement, or other theories based on the nature,
 
                                       19
<PAGE>
publication or distribution of this information. These types of claims have been
brought, sometimes successfully, against providers of Internet services in the
past. Such claims, with or without merit, would likely divert management time
and attention and result in significant costs to investigate and defend. In
addition, if we become subject to these types of claims and we are not
successful in our defense, we may be forced to pay substantial damages. We may
also be forced to implement expensive measures to alter the way our services are
provided to avoid any potential liability.
 
CHANGES IN GOVERNMENT REGULATION COULD DECREASE OUR REVENUES AND INCREASE OUR
  COSTS
 
    Changes in the regulatory environment could decrease our revenues and
increase our costs. As a provider of Internet access and e-mail services, we are
not currently subject to direct regulation by the Federal Communications
Commission. However, several telecommunications carriers are seeking to have
communications over the Internet regulated by the FCC in the same manner as
other more traditional telecommunications services. Local telephone carriers
have also petitioned the FCC to regulate Internet access providers in a manner
similar to long distance telephone carriers and to impose access fees on these
providers, and recent events suggest that they may be successful in obtaining
the treatment they seek. In addition, we operate our services throughout the
United States, and we cannot assure you that regulatory authorities at the state
level will not seek to regulate aspects of our activities as telecommunications
services. As a result, we could become subject to FCC and state regulation as
Internet services and telecommunications services converge.
 
    We remain subject to numerous additional laws and regulations that could
affect our business. Because of the Internet's popularity and increasing use,
new laws and regulations with respect to the Internet are becoming more
prevalent. These laws and regulations have covered, or may cover in the future,
issues such as:
 
    - user privacy;
 
    - pricing;
 
    - intellectual property;
 
    - federal, state and local taxation;
 
    - distribution; and
 
    - characteristics and quality of products and services.
 
    Legislation in these areas could slow the growth in use of the Internet
generally and decrease the acceptance of the Internet as a communications and
commercial medium. Additionally, because we rely on the collection and use of
personal data from our members for targeting advertisements shown on our
services, we may be harmed by any laws or regulations that restrict our ability
to collect or use this data. The Federal Trade Commission has begun
investigations into the privacy practices of companies that collect information
about individuals on the Internet. Although we are not currently subject to
direct regulation by the FTC, there can be no assurance that we will not become
subject to direct regulation in the future. It may take years to determine how
existing laws such as those governing intellectual property, privacy, libel and
taxation apply to the Internet. Any new legislation or regulation regarding the
Internet, or the application of existing laws and regulations to the Internet,
could harm us. Additionally, while we do not currently operate outside of the
United States, the international regulatory environment relating to the Internet
market could have an adverse effect on our business, especially if we should
expand internationally.
 
                                       20
<PAGE>
    The growth of the Internet, coupled with publicity regarding Internet fraud,
may also lead to the enactment of more stringent consumer protection laws. For
example, numerous bills have been presented to Congress and various state
legislatures designed to address the prevalence of unsolicited commercial bulk
e-mail on the Internet. These laws may impose additional burdens on our
business. The enactment of any additional laws or regulations in this area may
impede the growth of the Internet, which could decrease our potential revenues
or otherwise cause our business to suffer. Please see "Business--Government
Regulation."
 
IF INTERNET USAGE DOES NOT CONTINUE TO GROW, OUR BUSINESS WILL SUFFER
 
    Our business and financial results depend on continued growth in the use of
the Internet. We cannot be certain that this growth will continue or that it
will continue in its present form. If Internet usage declines or evolves away
from our business, our growth will slow or stop and our business and financial
results will suffer.
 
UNANTICIPATED DELAYS OR PROBLEMS IN THE INTRODUCTION OF NEW FEATURES OR SERVICES
  MAY CAUSE CUSTOMER DISSATISFACTION
 
    If we experience problems related to the reliability and quality of our
services or delays in the introduction of new versions of or enhancements to our
services, we could experience increased subscriber cancellations, adverse
publicity and reduced sales of advertising and products. Our services are very
complex and are likely to contain a number of undetected errors and defects,
especially when new features or enhancements are first released. These errors or
defects, if significant, could harm the performance of these services, result in
ongoing redevelopment and maintenance costs and/or cause dissatisfaction on the
part of subscribers and advertisers. These costs, delays or dissatisfaction
could negatively affect our business.
 
WE HAVE LIMITED EXPERIENCE WITH THE SOFTWARE WE USE TO BILL SUBSCRIBERS TO JUNO
  GOLD AND JUNO WEB
 
    The operation of Juno Gold and Juno Web requires the accurate operation of
billing system software as well as our development of policies designed to
reduce the incidence of credit card fraud and other forms of uncollectable
"chargebacks." We have only limited experience with the operation of these
billing and fraud detection systems. If we encounter difficulty with the
operation of these systems, or if errors, defects or malfunctions occur in the
operation of these systems, this could result in erroneous overcharges to
customers or in the under-collection of revenue, either of which could hurt our
business and financial results.
 
OUR RELATIONSHIP WITH D. E. SHAW & CO., L.P. MAY PRESENT POTENTIAL CONFLICTS OF
  INTEREST
 
    The Chairman of our board of directors and our controlling stockholder, Dr.
David E. Shaw, is the Chairman and Chief Executive Officer of D. E. Shaw & Co.,
Inc., which is the general partner of D. E. Shaw & Co., L.P., a global
securities firm whose activities focus on various aspects of the intersection
between technology and finance. Dr. Shaw devotes only a portion of his time to
our company, and spends most of his time and energy engaged in business
activities unrelated to us. Dr. Shaw indirectly owns a controlling interest in
DESCO, L.P. and in some of its affiliated entities. Transactions between us and
these parties may occur in the future and could potentially result in conflicts
of interest that prove harmful to us.
 
    We have historically contracted with DESCO, L.P. to provide accounting, tax,
payroll, insurance, employee benefits and information technology services, and
we continue to obtain some services from DESCO, L.P. These services are provided
to us on a fixed-fee basis under shared services agreements that can be
terminated by any of the parties without cause upon 90 days notice. We have also
entered into an agreement with DESCO, L.P. under which its affiliates located in
India provide consulting
 
                                       21
<PAGE>
   
services to us. If we were no longer able to obtain these services through
DESCO, L.P. or its affiliates, we would be required to obtain these services
internally or through third-party providers, and we cannot be sure that we could
do so on acceptable terms. In addition, we sublease office space in New York
City from DESCO, L.P. We cannot be sure that we would be able to lease other
space on favorable terms in the event the leases for this office space were to
be terminated.
    
 
    Dr. Shaw and entities affiliated with him are likely to manage, invest in or
otherwise be involved with other technology-related business ventures apart from
our company. These relationships could also restrict our ability to transact
business with non-affiliated parties, and could negatively affect us. For a more
detailed discussion of related-party transactions and our relationship with
entities affiliated with Dr. Shaw, please see "Certain Transactions."
 
OUR DIRECTORS AND OFFICERS WILL EXERCISE SIGNIFICANT CONTROL OVER US FOLLOWING
  THIS OFFERING
 
    We anticipate that the executive officers, directors and persons and
entities affiliated with executive officers and/or directors will, in the
aggregate, beneficially own approximately 53.3% of our outstanding common stock
following the completion of this offering. The Chairman of our board of
directors is Dr. David E. Shaw. Dr. Shaw continues to serve as the Chairman and
Chief Executive Officer of D. E. Shaw & Co., Inc., which is the general partner
of DESCO, L.P. Dr. Shaw and persons or entities affiliated with him, including
DESCO, L.P., will, in the aggregate, beneficially own approximately 50.1% of our
outstanding common stock following the completion of this offering. Following
the completion of this offering, Dr. Shaw will be able to exercise control over
all matters requiring approval by our stockholders, including the election of
directors and approval of significant corporate transactions. This concentration
of ownership could also have the effect of delaying or preventing a change in
control of Juno. Please see "Management" and "Principal Stockholders."
 
IF WE FAIL TO ADEQUATELY PROTECT OUR INTELLECTUAL PROPERTY OR FACE A CLAIM OF
  INTELLECTUAL PROPERTY INFRINGEMENT BY A THIRD PARTY, WE COULD LOSE OUR
  INTELLECTUAL PROPERTY RIGHTS OR BE LIABLE FOR SIGNIFICANT DAMAGES
 
    We have taken steps to protect our intellectual property rights, but we
cannot be certain that our efforts will be adequate to safeguard our rights to
technology we have developed. Disputes concerning the ownership or rights to use
intellectual property could be costly and time consuming to litigate, may
distract management from other tasks of operating the business, and may result
in our loss of significant rights and the loss of our ability to operate our
business.
 
    We have been granted three U.S. patents covering aspects of our technology
for the offline display of advertisements and aspects of our technology for the
authentication and dynamic scheduling of advertisements and other messages to be
delivered to computer users. We have also filed other U.S. patent applications
covering additional aspects of our business. We cannot assure you, however, that
these applications will result in the issuance of patents; that any patents that
have been granted or that might be granted in the future will provide us with
any competitive advantages or will be exploited profitably by us; or that any of
these patents will withstand any challenges by third parties. We also cannot
assure you that others will not obtain and assert patents against us which are
essential for our business. If patents are asserted against us, we cannot assure
you that we will be able to obtain license rights to those patents on reasonable
terms or at all. If we are unable to obtain licenses, we may be prevented from
operating our business and our financial results may therefore be harmed.
 
    Except as described above, we rely solely upon copyright and trademark law,
trade secret protection, and/or confidentiality agreements with our employees
and with some third parties to protect our proprietary technology, processes,
and other intellectual property, to the extent that protection is sought or
secured at all. We cannot assure you that any steps we might take will be
adequate to protect against infringement and misappropriation of our
intellectual property by third parties. Similarly, we
 
                                       22
<PAGE>
cannot assure you that third parties will not be able to independently develop
similar or superior technology, processes, or other intellectual property.
Furthermore, we cannot assure you that third parties will not assert claims
against us for infringement and misappropriation of their intellectual property
rights nor that others will not infringe or misappropriate our intellectual
property rights, for which we may wish to assert claims.
 
    Rights to all intellectual property that was developed for our business at
our expense by personnel assigned to Juno by DESCO, L.P. were originally held by
DESCO, L.P. Through a series of assignments, DESCO, L.P. subsequently
transferred to us its right, title and interest in this intellectual property.
In connection with these assignments, we agreed to indemnify DESCO, L.P. against
any claims relating to the assignment of, or the use of, this intellectual
property. We do not have any right, title, or interest in any other intellectual
property created, developed, produced, or used by DESCO, L.P.
 
PROBLEMS RESULTING FROM THE YEAR 2000 PROBLEM COULD REQUIRE US TO INCUR
  UNANTICIPATED EXPENSE AND COULD DIVERT MANAGEMENT'S TIME AND ATTENTION
 
    The Year 2000 problem could harm our business and financial results. Many
currently installed computer systems and software products are coded to accept
or recognize only two-digit entries in the date code field. These systems may
interpret the date code "00" as the year 1900 rather than the year 2000. As a
result, computer systems and/or software used by many companies and governmental
agencies may need to be upgraded or replaced to comply with Year 2000
requirements or risk system failure or miscalculations causing disruptions of
normal business activities. We have established procedures for evaluating and
managing the risks associated with the Year 2000 problem and we are in the
process of assessing our Year 2000 readiness. We are also in the process of
communicating with third-party vendors who provide us with both network services
and equipment in order to assess their plans and progress in addressing the Year
2000 problem. Our failure to correct a material Year 2000 problem could result
in an interruption in, or a failure of, aspects of our normal business
activities or operations. In addition, a significant Year 2000 problem involving
our network services or equipment provided to us by third-party vendors could
cause our customers to consider seeking alternate providers or cause an
unmanageable burden on our customer service and technical support capabilities.
Any significant Year 2000 problem could require us to incur significant
unanticipated expenses to remedy these problems and could divert management's
time and attention. Please see "Management's Discussion and Analysis of
Financial Condition and Results of Operations--Impact of the Year 2000" for
detailed information on our state of readiness, potential risks and contingency
plans regarding the Year 2000 issue.
 
WE ARE DEPENDENT ON KEY MANAGEMENT PERSONNEL FOR OUR FUTURE SUCCESS
 
    Our business and financial results depend in part on the continued service
of our key personnel. We do not carry key person life insurance on any of our
personnel. The loss of the services of any of our executive officers or the loss
of the services of other key employees could harm our business and financial
results. Mark A. Moraes, our Executive Vice President, Technology, is working at
Juno pursuant to an employment agreement with DESCO, L.P., under which he
performs services for Juno. In addition, Mr. Moraes is a citizen of India and
has been granted a waiver by the U.S. Immigration and Naturalization Service
which allows Mr. Moraes to obtain a "green card" for permanent residence status.
Since additional processing is required before the green card is issued, we
cannot assure you that Mr. Moraes will be issued a green card. Until Mr. Moraes
receives a green card, his ability to work in our U.S. offices is limited and,
in the event that he does not ultimately obtain a green card, it is likely that
he would be unable to work in our U.S. offices thereafter.
 
                                       23
<PAGE>
WE MAY NOT BE ABLE TO HIRE AND RETAIN QUALIFIED EMPLOYEES
 
    Our business and financial results depend in part on our ability to attract,
retain and motivate highly skilled employees. Competition for employees in our
industry is intense. We may be unable to retain our key employees or attract,
assimilate or retain other highly qualified employees. We have, from time to
time, in the past experienced, and we expect to continue to experience,
difficulty in hiring and retaining highly skilled employees with appropriate
qualifications.
 
WE CANNOT PREDICT OUR FUTURE CAPITAL NEEDS AND WE MAY NOT BE ABLE TO SECURE
  ADDITIONAL FINANCING
 
    We currently anticipate that the net proceeds of this offering, together
with available funds, will be sufficient to meet our anticipated needs for at
least the next 12 months. We may need to raise additional funds in the future to
fund our operations, to finance subscriber acquisition costs, to enhance and/or
expand the range of Internet services we offer or to respond to competitive
pressures and/or perceived opportunities. We cannot be sure that additional
financing will be available on terms favorable to us, or at all. If adequate
funds are not available or not available when required or on acceptable terms,
we may be forced to cease our operations, and even if we are able to continue
our operations, our business and financial results may suffer.
 
WE MAY NOT BE ABLE TO SUCCESSFULLY MAKE ACQUISITIONS OF OR INVESTMENTS IN OTHER
  COMPANIES
 
    We have no experience in acquiring or making investments in companies,
technologies or services. From time to time we have had discussions with
companies regarding our acquiring, or investing in, their businesses, products
or services, or customers. We have no present understanding or agreement
relating to any acquisition or investment. If we buy a company, we could have
difficulty in assimilating that company's personnel and operations. In addition,
the key personnel of the acquired company may decide not to work for us. If we
make other types of acquisitions, we could have difficulty in assimilating the
acquired services, technologies or customers into our operations. These
difficulties could disrupt our ongoing business, distract our management and
employees, increase our expenses and adversely affect our results of operations
due to accounting requirements such as the amortization of goodwill.
Furthermore, we may incur debt or issue equity securities to pay for any future
acquisitions. The issuance of equity securities could be dilutive to our
existing stockholders.
 
WE COULD FACE ADDITIONAL REGULATORY REQUIREMENTS, TAX LIABILITIES AND OTHER
  RISKS IF WE DECIDE TO EXPAND INTERNATIONALLY
 
    We may decide to expand internationally, and believe that any international
operations would be subject to most of the risks of our business generally. In
addition, there are risks inherent in doing business in international markets,
such as changes in regulatory requirements, tariffs and other trade barriers,
fluctuations in currency exchange rates, and adverse tax consequences, and there
are likely to be different consumer preferences and requirements in such
markets. We cannot assure you that one or more of these factors would not harm
any future international operations.
 
FUTURE SALES OF OUR COMMON STOCK MAY NEGATIVELY AFFECT OUR STOCK PRICE
 
    Following this offering, we will have a large number of shares of common
stock outstanding and available for resale beginning at various points in time
in the future. The market price of our common stock could decline as a result of
sales of a large number of shares of our common stock in the market following
this offering, or the perception that such sales could occur. These sales also
might make it more difficult for us to sell equity securities in the future at a
price that we think is appropriate, or at all. Please see "Shares Eligible for
Future Sale."
 
                                       24
<PAGE>
THERE HAS BEEN NO PRIOR MARKET FOR OUR COMMON STOCK AND OUR STOCK PRICE MAY
  EXPERIENCE EXTREME PRICE AND VOLUME FLUCTUATIONS
 
    The stock market has experienced extreme price and volume fluctuations. The
market prices of the securities of Internet-related companies have been
especially volatile. Prior to the offering, there has been no public market for
our common stock. We cannot predict the extent to which investor interest in
Juno will lead to the development of an active trading market or how liquid that
market might become. The market price of the common stock may decline below the
initial public offering price. The initial public offering price for the shares
will be determined by negotiations between us and the representatives of the
underwriters and may not be indicative of prices that will prevail in the
trading market. Please see "Underwriting."
 
    In the past, companies that have experienced volatility in the market price
of their stock have been the object of securities class action litigation. If we
were the object of securities class action litigation, it could result in
substantial costs and a diversion of our management's attention and resources.
 
WE MAY SPEND A SUBSTANTIAL PORTION OF THE NET PROCEEDS OF THIS OFFERING IN WAYS
  WITH WHICH YOU MAY NOT AGREE
 
    We intend to spend a significant portion of the net proceeds of this
offering on a marketing campaign and for the repayment of debt. Our management
will have broad discretion, however, over the allocation of a substantial
portion of the net proceeds from this offering as well as over the timing of our
expenditures. Investors may not agree with the way our management decides to
spend these proceeds. Please see "Use of Proceeds."
 
WE HAVE ANTI-TAKEOVER PROVISIONS WHICH MAY MAKE IT DIFFICULT FOR A THIRD PARTY
  TO ACQUIRE US
 
    Provisions of our certificate of incorporation, our bylaws and Delaware law
could make it more difficult for a third party to acquire us, even if doing so
might be beneficial to our stockholders. Please see "Description of Capital
Stock."
 
INVESTORS IN THIS OFFERING WILL SUFFER IMMEDIATE AND SUBSTANTIAL DILUTION
 
    Investors purchasing shares in the offering will incur immediate and
substantial dilution in net tangible book value per share. To the extent
outstanding options to purchase common stock are exercised, there will be
further dilution. Please see "Dilution."
 
WE DO NOT PLAN TO PAY DIVIDENDS IN THE FORESEEABLE FUTURE AND, AS A RESULT,
  STOCKHOLDERS WILL NEED TO SELL SHARES TO REALIZE A RETURN ON THEIR INVESTMENT
 
    We have not declared or paid any cash dividends on our capital stock since
inception. We intend to retain any future earnings to finance the operation and
expansion of our business and do not anticipate paying any cash dividends in the
foreseeable future. Consequently, stockholders will need to sell shares of
common stock in order to realize a return on their investment, if any.
 
                           FORWARD-LOOKING STATEMENTS
 
    This prospectus contains forward-looking statements which involve risks and
uncertainties. These forward-looking statements are usually accompanied by words
such as "believes," "anticipates," "plans," "expects" and similar expressions.
Our actual results could differ materially from those expressed or implied by
these forward-looking statements as a result of various factors, including the
risk factors described above and elsewhere in this prospectus.
 
                                       25
<PAGE>
                                USE OF PROCEEDS
 
    The net proceeds to us from the sale of the 6,500,000 shares offered hereby,
after deducting the underwriting discounts and estimated offering expenses
payable by us, are estimated to be approximately $71.5 million, or $82.4 million
if the underwriters' over-allotment option is exercised in full, assuming an
initial public offering price of $12.00 per share.
 
    We intend to use the net proceeds of this offering for subscriber
acquisition, advertising, brand marketing, continued investment in the
development of our Internet services, enhancements of our network infrastructure
and other general corporate purposes. We also intend to use the net proceeds of
this offering to repay all indebtedness to D. E. Shaw Securities Group, L.P., an
affiliated party, which totalled $8.8 million as of March 31, 1999. This
indebtedness bears interest at the Federal Funds rate plus 0.375%, which
totalled 5.355% as of March 31, 1999, and matures upon the earlier of December
31, 2000 or the date of completion of an initial public offering. Juno
originally borrowed this money for working capital and other general corporate
purposes. We may also use a portion of the proceeds of this offering for
acquisitions, strategic alliances, or joint ventures. At present, we have no
plans, arrangements or understandings related to any specific acquisitions.
 
    Other than the repayment of debt, we have not yet determined the amount of
net proceeds to be used specifically for each of the foregoing purposes.
Accordingly, management will have significant flexibility in applying a
substantial portion of the net proceeds of the offering. Until this money is
used, we intend to invest the net proceeds in interest-bearing instruments.
 
                                DIVIDEND POLICY
 
    We have not declared or paid any cash dividends on our capital stock since
inception. We intend to retain any future earnings to finance the operation and
expansion of our business and do not anticipate paying any cash dividends in the
foreseeable future. Consequently, stockholders will need to sell shares of
common stock in order to realize a return on their investment, if any.
 
                                       26
<PAGE>
                                 CAPITALIZATION
 
    The following table sets forth, as of March 31, 1999, the capitalization of
Juno on an actual basis and on a basis which assumes the completion of this
offering by giving effect to the following:
 
    - the sale of the 6,500,000 shares offered hereby at an assumed initial
      public offering price of $12.00 per share, after deducting the
      underwriting discounts and estimated offering expenses payable by Juno,
      and the application of the net proceeds from this offering; and
 
    - the automatic conversion of all outstanding shares of redeemable
      convertible preferred stock into 27,822,751 shares of common stock upon
      the closing of this offering.
 
    This information should be read in conjunction with Juno's consolidated
financial statements and the notes relating to these statements appearing
elsewhere in this prospectus.
 
<TABLE>
<CAPTION>
                                                                                               MARCH 31, 1999
                                                                                          ------------------------
                                                                                            ACTUAL     AS ADJUSTED
                                                                                          -----------  -----------
<S>                                                                                       <C>          <C>
                                                                                               (IN THOUSANDS)
Total indebtedness, including current maturities........................................  $     9,930   $   1,118
                                                                                          -----------  -----------
Redeemable convertible preferred stock, $.01 par value:
  Series B: 10,138,716 shares
    authorized, issued and outstanding on an actual basis; none
    authorized, issued or outstanding on
    an as adjusted basis................................................................       61,853      --
  Series A: 17,684,035 shares
    authorized, issued and outstanding on an actual basis; none
    authorized, issued or outstanding on
    an as adjusted basis................................................................       79,578      --
Stockholders' equity (deficit):
  Preferred Stock, $.01 par value, 5,000,000 shares authorized; none issued or
    outstanding on an actual or as adjusted basis.......................................      --           --
  Common Stock, $.01 par value, 133,333,334 shares authorized; 251,229 shares issued and
    outstanding on an actual basis; and 34,573,980 shares issued and outstanding on an
    as adjusted basis...................................................................            3         346
  Additional paid-in capital............................................................      (95,724)    116,904
  Unearned compensation.................................................................         (691)       (691)
  Accumulated deficit...................................................................       (2,417)     (2,417)
                                                                                          -----------  -----------
    Total stockholders' equity (deficit)................................................      (98,829)    114,142
                                                                                          -----------  -----------
      Total capitalization..............................................................  $    52,532   $ 115,260
                                                                                          -----------  -----------
                                                                                          -----------  -----------
</TABLE>
 
   
    The table above excludes 3,241,480 shares of common stock issuable upon the
exercise of stock options outstanding as of May 5, 1999, with a weighted average
exercise price of $4.27 per share. See "Management--1999 Stock Incentive Plan,"
"Description of Capital Stock" and Note 11 of Notes to Consolidated Financial
Statements.
    
 
                                       27
<PAGE>
                                    DILUTION
 
    The pro forma net tangible book value of Juno as of March 31, 1999, after
giving effect to the automatic conversion of 17,684,035 shares of Series A
redeemable convertible preferred stock and 10,138,716 shares of Series B
redeemable convertible preferred stock into common stock, was $42.6 million, or
$1.52 per share of common stock. Pro forma net tangible book value per share is
equal to the amount of Juno's total tangible assets, which is defined as total
assets less intangible assets, divided by the number of shares of common stock
outstanding, on a pro forma basis, as of March 31, 1999. Assuming the sale by
Juno of the 6,500,000 shares offered hereby at an assumed initial public
offering price of $12.00 per share and after deducting underwriting discounts
and estimated offering expenses, and the application of the estimated net
proceeds therefrom, the pro forma net tangible book value of Juno as of March
31, 1999 would have been $114.1 million, or $3.30 per share of common stock.
This represents an immediate increase in pro forma net tangible book value of
$1.78 per share to existing stockholders and an immediate dilution in pro forma
net tangible book value of $8.70 per share to new investors. The following table
illustrates this per share dilution:
 
<TABLE>
<S>                                                                           <C>        <C>
Assumed initial public offering price per share.............................             $   12.00
  Pro forma net tangible book value per share as of March 31, 1999..........  $    1.52
  Pro forma increase attributable to new investors..........................       1.78
                                                                              ---------
Pro forma net tangible book value per share after the offering..............                  3.30
                                                                                         ---------
Pro forma dilution per share to new investors...............................             $    8.70
                                                                                         ---------
                                                                                         ---------
</TABLE>
 
    The following table summarizes, on a pro forma basis as of March 31, 1999,
after giving effect to the automatic conversion of all outstanding shares of
preferred stock into common stock, the total number of shares of common stock
purchased from Juno, the total consideration paid to Juno and the average price
per share paid by existing stockholders and by new investors:
 
<TABLE>
<CAPTION>
                                                        SHARES PURCHASED           TOTAL CONSIDERATION
                                                    -------------------------  ---------------------------  AVERAGE PRICE
                                                       NUMBER       PERCENT        AMOUNT        PERCENT      PER SHARE
                                                    ------------  -----------  --------------  -----------  -------------
<S>                                                 <C>           <C>          <C>             <C>          <C>
Existing stockholders.............................    28,073,980        81.2%  $  144,578,130        65.0%    $    5.15
New investors.....................................     6,500,000        18.8       78,000,000        35.0         12.00
                                                    ------------       -----   --------------       -----
    Total.........................................    34,573,980       100.0%  $  222,578,130       100.0%
                                                    ------------       -----   --------------       -----
                                                    ------------       -----   --------------       -----
</TABLE>
 
   
    The foregoing tables and calculations assume no exercise of outstanding
options. At May 5, 1999, there were 3,241,480 shares of common stock reserved
for issuance upon exercise of outstanding options at a weighted average exercise
price of $4.27 per share. To the extent that these options are exercised, there
will be further dilution to new investors. See "Management--1999 Stock Incentive
Plan."
    
 
                                       28
<PAGE>
                      SELECTED CONSOLIDATED FINANCIAL DATA
 
    The following selected consolidated financial data should be read in
conjunction with the consolidated financial statements and the notes to these
statements and "Management's Discussion and Analysis of Financial Condition and
Results of Operations" included elsewhere in this prospectus. The consolidated
statement of operations data for the period from our inception on June 30, 1995
through December 31, 1995 and for the years ended December 31, 1996, 1997 and
1998, and the consolidated balance sheet data at December 31, 1995, 1996, 1997
and 1998, are derived from the consolidated financial statements of Juno which
have been audited by PricewaterhouseCoopers LLP, independent accountants, and
are included elsewhere in this prospectus. The unaudited consolidated financial
statements have been prepared on substantially the same basis as the audited
consolidated financial statements and include all adjustments, consisting of
normal recurring adjustments, which Juno considers necessary for a fair
presentation of the financial position and results of operations for those
periods. Operating results for the three months ended March 31, 1999 are not
necessarily indicative of the results that may be expected for any other
three-month period or for the year ended December 31, 1999.
 
   
    Net loss per share for the three months ended March 31, 1999 is calculated
separately for the periods prior and subsequent to the March 1999 statutory
merger. The pro forma information regarding net loss per share and weighted
average shares outstanding set forth below gives effect to the treatment of
Class A limited partnership units as shares of common stock for all periods
presented and the conversion of Series B redeemable convertible preferred stock
for the period following the March 1999 statutory merger. See the consolidated
financial statements and the notes to these statements appearing elsewhere in
this prospectus for the determination of the number of shares used in computing
historical and pro forma basic and diluted loss per share.
    
<TABLE>
<CAPTION>
                                                      PERIOD FROM
                                                       INCEPTION
                                                       (JUNE 30,                                                 THREE MONTHS
                                                         1995)             YEAR ENDED DECEMBER 31,             ENDED MARCH 31,
                                                      TO DECEMBER   -------------------------------------  ------------------------
                                                       31, 1995        1996         1997         1998         1998         1999
                                                     -------------  -----------  -----------  -----------  -----------  -----------
<S>                                                  <C>            <C>          <C>          <C>          <C>          <C>
                                                                                                                 (UNAUDITED)
 
<CAPTION>
                                                                         (IN THOUSANDS, EXCEPT PER SHARE DATA)
</TABLE>
 
<TABLE>
<S>                                                 <C>          <C>          <C>          <C>          <C>          <C>
STATEMENT OF OPERATIONS DATA:
  Revenues:
    Billable services.............................   $      --    $       6    $   1,371    $   6,645    $     465    $   5,806
    Advertising and transaction fees..............          --          127        1,875        6,454        1,228        2,265
    Direct product sales..........................          --            3        5,845        8,595        2,577        1,649
                                                    -----------  -----------  -----------  -----------  -----------  -----------
      Total revenues..............................          --          136        9,091       21,694        4,270        9,720
                                                    -----------  -----------  -----------  -----------  -----------  -----------
  Cost of revenues:
    Billable services.............................          --           --        1,053        5,606          387        4,678
    Advertising and transaction fees..............          --          278        1,659        3,725          825        1,080
    Direct product sales..........................          --            3        5,796        7,627        2,426        1,424
                                                    -----------  -----------  -----------  -----------  -----------  -----------
      Total cost of revenues......................          --          281        8,508       16,958        3,638        7,182
                                                    -----------  -----------  -----------  -----------  -----------  -----------
  Operating expenses:
    Operations, free service......................          --        5,803       11,075        9,383        2,824        1,846
    Subscriber acquisition........................         592        6,993        3,140        5,334        1,453        2,700
    Sales and marketing...........................         389        4,276       12,593       11,584        4,270        2,312
    Product development...........................       2,577        3,741        4,860        7,345        1,835        1,854
    General and administrative....................         275        2,172        2,897        2,760          914          704
                                                    -----------  -----------  -----------  -----------  -----------  -----------
      Total operating expenses....................       3,833       22,985       34,565       36,406       11,296        9,416
                                                    -----------  -----------  -----------  -----------  -----------  -----------
      Loss from operations........................      (3,833)     (23,130)     (33,982)     (31,670)     (10,664)      (6,878)
  Interest income, net............................          --          128          243           44           74          111
                                                    -----------  -----------  -----------  -----------  -----------  -----------
      Net loss....................................   $  (3,833)   $ (23,002)   $ (33,739)   $ (31,626)   $ (10,590)   $  (6,767)
                                                    -----------  -----------  -----------  -----------  -----------  -----------
                                                    -----------  -----------  -----------  -----------  -----------  -----------
</TABLE>
 
                                       29
<PAGE>
   
<TABLE>
<CAPTION>
                                                                                                          THREE MONTHS
                                     PERIOD FROM                                                        ENDED MARCH 31,
                                      INCEPTION                                                    --------------------------
                                      (JUNE 30,                                                     TWO MONTHS
                                        1995)          YEAR ENDED DECEMBER 31,                         ENDED      MONTH ENDED
                                     TO DECEMBER   -------------------------------                 FEBRUARY 28,    MARCH 31,
                                      31, 1995       1996       1997       1998                        1999          1999
                                    -------------  ---------  ---------  ---------                 -------------  -----------
                                                                                    THREE MONTHS
                                                                                        ENDED
                                                                                      MARCH 31,
                                                                                        1998
                                                                                    -------------
                                                                                     (UNAUDITED)          (UNAUDITED)
<S>                                 <C>            <C>        <C>        <C>        <C>            <C>            <C>
                                                              (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<CAPTION>
 
                                      TOTAL
                                    ---------
 
<S>                                 <C>
 
</TABLE>
    
 
   
<TABLE>
<S>                                <C>        <C>        <C>        <C>        <C>            <C>            <C>          <C>
EARNINGS PER SHARE CALCULATION:
  Net loss.......................  $  (3,833) $ (23,002) $ (33,739) $ (31,626)   $ (10,590)     $  (4,350)    $  (2,417)  $  (6,767)
                                   ---------  ---------  ---------  ---------  -------------  -------------  -----------  ---------
                                   ---------  ---------  ---------  ---------  -------------  -------------  -----------  ---------
  Net loss attributable to common
    stockholders.................  $  (3,833) $ (23,002) $ (33,739) $ (31,626)   $ (10,590)     $  (4,350)    $  (3,589)  $  (6,767)
                                   ---------  ---------  ---------  ---------  -------------  -------------  -----------  ---------
                                   ---------  ---------  ---------  ---------  -------------  -------------  -----------  ---------
  Weighted average number of:
    Class A limited partnership
      units......................        519      3,281     10,500     17,091       16,054         17,684
                                   ---------  ---------  ---------  ---------  -------------  -------------
                                   ---------  ---------  ---------  ---------  -------------  -------------
    Shares of Common Stock.......                                                                                   217
                                                                                                             -----------
                                                                                                             -----------
  Basic and diluted net loss per
    Class A limited partnership
    unit.........................  $   (7.39) $   (7.01) $   (3.21) $   (1.85)   $   (0.66)     $   (0.25)
                                   ---------  ---------  ---------  ---------  -------------  -------------
                                   ---------  ---------  ---------  ---------  -------------  -------------
  Basic and diluted net loss per
    share........................                                                                             $  (16.54)
                                                                                                             -----------
                                                                                                             -----------
  Pro forma basic and diluted net
    loss per share...............                                   $   (1.85)                                            $   (0.32)
                                                                    ---------                                             ---------
                                                                    ---------                                             ---------
  Weighted average shares
    outstanding used in pro forma
    basic and diluted per share
    calculation..................                                      17,091                                                21,225
                                                                    ---------                                             ---------
                                                                    ---------                                             ---------
</TABLE>
    
<TABLE>
<CAPTION>
                                                                             DECEMBER 31,                  MARCH 31,
                                                              ------------------------------------------  -----------
                                                                1995       1996       1997       1998        1999
                                                              ---------  ---------  ---------  ---------  -----------
<S>                                                           <C>        <C>        <C>        <C>        <C>
                                                                                                          (UNAUDITED)
 
<CAPTION>
                                                                                  (IN THOUSANDS)
<S>                                                           <C>        <C>        <C>        <C>        <C>
BALANCE SHEET DATA:
  Cash and cash equivalents.................................  $      --  $     598  $  13,770  $   8,152   $  53,165
  Working capital (deficiency)..............................         92     (2,004)     6,927     (8,343)     48,000
  Total assets..............................................         92      4,774     20,133     14,703      71,660
  Total indebtedness, including current maturities..........         --         --        795     10,188       9,930
  Redeemable convertible preferred stock....................         --         --         --         --     141,431
  Partners' capital (deficiency)............................         92     (2,004)    10,504    (12,588)         --
  Total stockholders' equity (deficit)......................         --         --         --         --     (98,829)
</TABLE>
 
                                       30
<PAGE>
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
    THE FOLLOWING DISCUSSION OF THE FINANCIAL CONDITION AND RESULTS OF
OPERATIONS OF JUNO SHOULD BE READ IN CONJUNCTION WITH THE CONSOLIDATED FINANCIAL
STATEMENTS AND THE NOTES TO THOSE STATEMENTS INCLUDED ELSEWHERE IN THIS
PROSPECTUS. THIS DISCUSSION CONTAINS FORWARD-LOOKING STATEMENTS THAT INVOLVE
RISKS AND UNCERTAINTIES. JUNO'S ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE
ANTICIPATED IN THESE FORWARD-LOOKING STATEMENTS AS A RESULT OF VARIOUS FACTORS,
SUCH AS THOSE SET FORTH UNDER "RISK FACTORS" AND ELSEWHERE IN THIS PROSPECTUS.
 
OVERVIEW
 
    Juno Online Services, Inc. is a leading provider of Internet-related
services to millions of computer users throughout the United States. We offer
several levels of service, ranging from basic dial-up Internet e-mail--which is
provided to the end user for free--to full, competitively priced access to the
World Wide Web. Our revenues are derived primarily from the fees we charge for
the use of our billable subscription services, from the sale of advertising, and
from the direct sale of products to our subscribers.
 
    Our business strategy has encompassed two phases. The initial phase, which
began at our inception in June 1995, focused on building computer systems and
related infrastructure that could be rapidly expanded to accommodate increasing
numbers of users, and on maximizing the number of subscribers to our free basic
e-mail service, which launched in April 1996. In July 1998, we commenced the
second phase of our business strategy by introducing two additional service
levels: an enhanced e-mail service, JUNO GOLD, and a full Internet access
service, JUNO WEB.
 
    We classify our revenues as follows:
 
    (1) Billable services revenues, consisting of:
 
       (a) subscription fees from subscribers to Juno Gold and Juno Web, our
           billable subscription services;
 
       (b) technical support fees received when subscribers to our free basic
           e-mail service and to Juno Gold call a 900 number for live assistance
           from a support technician; and
 
       (c) charges for shipping and handling associated with mailing disks upon
           request to prospective Juno subscribers, consulting revenues, and
           fees for other billable services.
 
    (2) Advertising and transaction fees, consisting of revenues earned from
       advertisers and strategic marketing partners for displaying
       advertisements to, and facilitating electronic commerce with, our
       subscribers. The majority of these advertisements are displayed while a
       Juno subscriber reads or writes e-mail offline. Advertising revenues are
       also derived from banner ad impressions displayed to Juno Web subscribers
       when they use our portal Web site, to which they are automatically
       brought each time they use Juno to connect to the Web.
 
    (3) Direct product sales, consisting of revenues generated from the sale of
       products directly by us to our subscribers and the associated shipping
       and handling fees.
 
    The commencement of the second phase of our business strategy has affected
the composition of our revenues. On July 22, 1998, we launched our billable
subscription services, and as of March 31, 1999, we had approximately 207,000
billable service subscribers, consisting of approximately 86,000 Juno Gold
subscribers and approximately 121,000 Juno Web subscribers. Since the launch of
our billable subscription services, billable services revenues have increased,
both in absolute terms and as a percentage of our revenues.
 
    We currently offer our billable subscription services under a number of
pricing plans, ranging from $2.95 per month for Juno Gold, billed annually in
advance, to $19.95 per month for the Juno Web
 
                                       31
<PAGE>
flat-rate plan. In marketing the Juno Web service, we have typically offered a
number of promotions, such as a free month of service or a discounted rate for
an initial period. Revenues for these billable subscription services accounted
for approximately 86.2% of billable services revenues during the first quarter
of 1999.
 
    Our strategy contemplates considerable growth in the number of subscribers
to our billable subscription services. We intend to devote significant resources
to advertising, brand marketing and referral programs designed to acquire new
subscribers directly into our billable subscription services and to encourage
migration of our free basic e-mail subscribers to these billable services. We
expect growth in the subscriber base for Juno Gold and Juno Web to result in
substantial growth in subscription fees, both in absolute dollar terms and as a
percentage of total revenues. Our strategy contemplates that revenues for
billable subscription services are likely to be the single largest source of
revenues for Juno in the immediate future.
 
    We are subject to industry trends that affect Internet access providers
generally, including seasonality and subscriber cancellations. We believe
Internet access providers typically incur higher expenses during the last and
first calendar quarters, corresponding to heavier usage during the fall and
winter, and experience relatively lighter usage and relatively fewer account
registrations during the summer. We believe subscriber acquisition also tends to
be most effective during the first and last calendar quarters of each year, and
we may take these types of seasonal effects into consideration in scheduling our
marketing activities. The results of operations of Internet access providers,
including those of Juno, are significantly affected by subscriber cancellations.
The failure to retain subscribers to our billable subscription services, or an
increase in the rate of cancellations of those services, would cause our
business and financial results to suffer.
 
    Additionally, our strategy contemplates increases in revenues from
advertising and transaction fees. We expect that strategic marketing alliances
will account for an increasing portion of such revenues. This is due in part to
our expectation that we may secure additional strategic marketing alliances, as
well as to our expectation that we may earn incremental performance-based
revenues beyond the minimum guaranteed revenues associated with some of these
arrangements. Furthermore, we expect that revenues from direct product sales
will decline in the future as a percentage of total revenues due to our
strategic decision to focus increasingly on higher margin activities.
 
    Our principal expenses consist of marketing, telecommunications, customer
service, personnel and related costs, and the cost of direct product sales. We
have elected to obtain telecommunications services, customer service and
merchandising fulfillment principally from third-party providers.
 
    We have incurred net losses of $99.0 million from our inception on June 30,
1995 through March 31, 1999. In addition, we have recorded cumulative unearned
compensation of $762,000, which represents the difference between the exercise
price and the deemed fair market value at the date of grant for shares of common
stock issuable upon the exercise of stock options. Of the total unearned
compensation amount, $34,000 was amortized for the year ended December 31, 1998
and $37,000 was amortized for the three months ended March 31, 1999. The
remaining unearned compensation amount is expected to be amortized over the
remaining vesting periods of the related options. In April 1999, we recorded an
additional $612,000 of unearned compensation for additional options granted to
purchase shares of common stock.
 
    We have relied on private sales of equity securities, totaling $79.6 million
through December 31, 1998, and borrowings to fund our operations. In March 1999,
we raised an additional $61.8 million of net proceeds through the private
placement of Series B redeemable convertible preferred stock. We expect net
losses to continue for the foreseeable future as we continue to incur
significant expenses while pursuing our business strategy.
 
                                       32
<PAGE>
    Prior to March 1, 1999, we operated our business primarily through a limited
partnership, Juno Online Services, L.P. On that date, we completed a statutory
merger of Juno Online Services, L.P. into Juno Online Services, Inc., which had
been a wholly owned subsidiary of Juno Online Services, L.P. Juno Online
Services, Inc. is the surviving entity after completion of the statutory merger.
The consolidated financial statements included in the prospectus consist of the
accounts of both Juno Online Services, L.P. and Juno Online Services, Inc. All
significant intercompany accounts and transactions have been eliminated in
consolidation. Since we operated as a limited partnership prior to March 1,
1999, taxable losses incurred through that date have been allocated to the
partners for reporting on their respective income tax returns. Accordingly, as
of that date, we had no available net operating loss carryforwards available for
federal and state income tax purposes to offset future taxable income, if any.
 
RESULTS OF OPERATIONS
 
THREE MONTHS ENDED MARCH 31, 1999 COMPARED TO THREE MONTHS ENDED MARCH 31, 1998
 
    REVENUES
 
    Total revenues increased approximately $5.5 million, from $4.3 million for
the three months ended March 31, 1998 to $9.7 million for the three months ended
March 31, 1999, an increase of 128%. This increase was due primarily to
increases in billable services and in advertising and transaction fees,
partially offset by a decrease in direct product sales.
 
    BILLABLE SERVICES.  Billable services revenues increased $5.3 million, from
$0.5 million for the three months ended March 31, 1998 to $5.8 million for the
three months ended March 31, 1999, an increase of 1,149%. This increase was due
primarily to the introduction of our billable subscription services in July
1998, which contributed $5.0 million of revenues in the three months ended March
31, 1999. At March 31, 1999, there were approximately 207,000 billable service
subscribers, with approximately 86,000 subscribing to Juno Gold and
approximately 121,000 subscribing to Juno Web.
 
    ADVERTISING AND TRANSACTION FEES.  Advertising and transaction fees
increased approximately $1.0 million, from $1.2 million for the three months
ended March 31, 1998 to $2.3 million for the three months ended March 31, 1999,
an increase of 84.4%. This increase was due to additional revenue from a larger
number of strategic marketing alliances. This increase was also due in part to a
contribution from revenue recognized over the shortened life of a strategic
marketing alliance which featured a minimum revenue guarantee and which was
terminated by the strategic partner effective May 1, 1999. This contribution
accounted for approximately 23.0% of advertising and transaction fees for the
three months ended March 31, 1999. The increase in advertising and transaction
fees was partially offset by declines in the number of and the aggregate revenue
generated from shorter-term ad sales contracts, reflecting our shift in emphasis
towards larger strategic deals.
 
    DIRECT PRODUCT SALES.  Direct product sales decreased approximately $0.9
million, from $2.6 million for the three months ended March 31, 1998 to $1.6
million for the three months ended March 31, 1999, a decrease of 36.0%. This
decline reflects our strategic decision in 1998 to narrow the range of our
direct product sales activities and of the types of products offered to our
subscribers. Instead, we decided to concentrate on forming strategic marketing
alliances and developing other uses for our advertising inventory that we
believe should generate revenues with higher margins than direct product sales.
 
    COST OF REVENUES
 
    Total cost of revenues increased approximately $3.5 million, from $3.6
million for the three months ended March 31, 1998 to $7.2 million for the three
months ended March 31, 1999, an increase of 97.4%. This increase was due
primarily to increases in costs associated with billable services and in
 
                                       33
<PAGE>
advertising and transaction fees, partially offset by a decrease in costs
associated with direct product sales.
 
    BILLABLE SERVICES.  Cost of revenues related to billable services consists
primarily of the costs to provide Juno Gold and Juno Web, including
telecommunications, customer service, operator-assisted technical support,
credit card fees, and personnel and related overhead costs. In addition, cost of
revenues related to billable services includes the costs of mailing disks upon
request to prospective Juno subscribers, and the personnel and related overhead
costs associated with our performance of a short-term consulting engagement
during the three months ended March 31, 1999.
 
    Cost of revenues related to billable services increased $4.3 million, from
$0.4 million for the three months ended March 31, 1998 to $4.7 million for the
three months ended March 31, 1999, an increase of 1,109%. This increase was due
primarily to the costs of providing our billable subscription services. Costs
related to the provision of these billable subscription services, principally
customer service, technical support and telecommunications expenses, accounted
for 76.1% of the total costs of revenues related to billable services during the
three months ended March 31, 1999 and accounted for the majority of the
increase. Cost of revenues as a percentage of billable services revenues
decreased from 83.1% for the three months ended March 31, 1998 to 80.6% for the
three months ended March 31, 1999. This decrease is primarily attributable to
the introduction of billable subscription services and the higher margins
realized from those services during the three months ended March 31, 1999.
 
    ADVERTISING AND TRANSACTION FEES.  Cost of revenues for advertising and
transaction fees consists primarily of the transmission costs associated with
downloading advertisements to the hard drives of subscribers' computers for
later display, the personnel and related costs associated with the creation and
distribution of such advertisements, and the costs associated with reporting the
results of ad campaigns to advertisers.
 
    Cost of revenues for advertising and transaction fees increased $0.3
million, from $0.8 million for the three months ended March 31, 1998 to $1.1
million for the three months ended March 31, 1999, an increase of 30.8%. This
increase was due primarily to the impact of additional strategic marketing
alliances. Cost of revenues related to advertising and transaction fees as a
percentage of advertising and transaction fees decreased from 67.2% for the
three months ended March 31, 1998 to 47.7% for the three months ended March 31,
1999. This decrease is primarily due to a contribution from revenue recognized
over the shortened life of a strategic marketing alliance that featured a
minimum revenue guarantee, and also to decreased telecommunications rates,
faster average connection speeds and improvements in our production and
distribution methods.
 
    DIRECT PRODUCT SALES.  Cost of revenues for direct product sales consists
primarily of the costs of merchandise sold directly by us to our subscribers and
the associated shipping and handling costs.
 
    The cost of revenues for direct product sales decreased $1.0 million, from
$2.4 million for the three months ended March 31, 1998 to $1.4 million for the
three months ended March 31, 1999, a decrease of 41.3%. This decrease
corresponds to the decrease in merchandise sold. The cost of revenues for direct
product sales as a percentage of direct product sales revenues decreased from
94.1% for the three months ended March 31, 1998 to 86.3% for the three months
ended March 31, 1999. This decrease was primarily due to efficiencies associated
with outsourcing various functions rather than performing them internally.
 
    OPERATING EXPENSES
 
    OPERATIONS, FREE SERVICE.  Operations, free service consists of the costs
associated with providing our free basic e-mail service, comprising principally
telecommunications costs, expenses associated with
 
                                       34
<PAGE>
providing customer service, depreciation of network equipment, and personnel and
related overhead costs.
 
    Expenses associated with operations, free service decreased $1.0 million,
from $2.8 million for the three months ended March 31, 1998 to $1.8 million for
the three months ended March 31, 1999, a decrease of 34.6%. This decrease was
primarily due to declining telecommunications rates and increasing connection
speeds resulting from the use of faster modems by a portion of our subscriber
base.
 
    SUBSCRIBER ACQUISITION.  Subscriber acquisition costs include all costs
incurred to acquire subscribers to either our free basic e-mail service or one
of our billable subscription services. These costs include direct mail
campaigns, advertising through conventional and computer-based media,
telemarketing, producing advertisements to be displayed over the Juno services
and transmitting them to our subscribers, disk duplication and fulfillment, and
bounties paid to acquire subscribers, among other marketing activities. These
costs also include various subscriber retention activities, as well as personnel
and related overhead costs.
 
    Subscriber acquisition costs increased $1.2 million, from $1.5 million for
the three months ended March 31, 1998 to $2.7 million for the three months ended
March 31, 1999, an increase of 85.8%. This increase is primarily due to ad
production and transmission costs associated with soliciting basic e-mail
subscribers to upgrade to our billable subscription services, costs associated
with preparations for large-scale marketing activities scheduled to begin in the
second quarter of 1999 and inbound telemarketing costs incurred in connection
with subscriber acquisition and retention activities. The increase in these
costs was partially offset by a decrease in expenses related to referral
bounties as various agreements that called for bounty payments expired or were
terminated. As a percentage of revenues, subscriber acquisition costs decreased
from 34.0% in the three months ended March 31, 1998 to 27.8% in the three months
ended March 31, 1999. This percentage decrease was primarily due to the increase
in revenues for the three months ended March 31, 1999. We expect that subscriber
acquisition costs will increase significantly both in absolute dollar terms and
as a percentage of total revenues in the future.
 
    SALES AND MARKETING.  Sales and marketing expenses consist primarily of the
personnel and related overhead costs of the following departments: advertising
sales and business development; direct product sales; and product marketing.
Also included are costs associated with trade advertising intended to support
our ad sales effort, corporate branding activities unrelated to subscriber
acquisition, and public relations, as well as ad production, ad transmission,
customer service and fulfillment costs associated with our direct product sales
activities.
 
    Sales and marketing costs decreased $2.0 million, from $4.3 million for the
three months ended March 31, 1998 to $2.3 million for the three months ended
March 31, 1999, a decrease of 45.8%. This decrease is primarily due to cost
savings associated with our decision to narrow the range of our direct product
sales activities. We reduced the headcount assigned to our direct product sales
activities, as well as our inventory risk, primarily by outsourcing
substantially all of the procurement, warehousing, fulfillment, billing and
customer service aspects of the initiative. Sales and marketing expenses for the
three months ended March 31, 1998 include charges of approximately $0.3 million
relating to inventory write-offs and severance pay. As a percentage of revenues,
sales and marketing costs decreased from 100.0% in the three months ended March
31, 1998 to 23.8% in the three months ended March 31, 1999. This percentage
decrease was primarily due to the increase in revenues for the three months
ended March 31, 1999.
 
    PRODUCT DEVELOPMENT.  Product development includes research and development
expenses and other product development costs. These costs consist primarily of
personnel and related overhead costs as well as the costs associated with
research and development and other product development activities performed for
us on a contract basis by a related party in Hyderabad, India.
 
                                       35
<PAGE>
    Product development costs increased approximately $19,000, from $1.8 million
for the three months ended March 31, 1998 to $1.9 million for the three months
ended March 31, 1999, an increase of 1.0%. Product development costs in the
three months ended March 31, 1998 and 1999 related primarily to the continued
development of our billable subscription services and of various pieces of
software. To date, we have not capitalized any expenses related to any software
development activities.
 
    GENERAL AND ADMINISTRATIVE.  General and administrative expenses consist
primarily of personnel and related overhead costs associated with executive,
finance, legal, recruiting, human resources and facilities functions, as well as
various professional expenses.
 
    General and administrative costs decreased $0.2 million, from $0.9 million
for the three months ended March 31, 1998 to $0.7 million for the three months
ended March 31, 1999, a decrease of 23.0%. This decrease is primarily due to
reduced personnel and related overhead costs and cost containment programs. As a
percentage of revenues, general and administrative costs decreased from 21.4% in
the three months ended March 31, 1998 to 7.2% for the three months ended March
31, 1999. This decrease was primarily due to the increase in revenue for the
three months ended March 31, 1999. We expect that we will incur additional
general and administrative expenses as we hire additional personnel and incur
additional costs related to the growth of our business and our operation as a
public company, including directors' and officers' liability insurance, investor
relations programs and professional service fees. Accordingly, we anticipate
that general and administrative expenses will increase in absolute dollar terms
in the future.
 
    INTEREST INCOME, NET.  Interest income, net increased $37,000, from $74,000
for the three months ended March 31, 1998 to $111,000 for the three months ended
March 31, 1999, an increase of 50.1%. This increase is primarily due to interest
income earned on higher average cash balances in the three months ended March
31, 1999 due to the receipt of $61.8 million of net proceeds in exchange for the
issuance of redeemable convertible preferred stock in March 1999, partially
offset by higher interest payments for borrowings.
 
YEAR ENDED DECEMBER 31, 1998 COMPARED TO YEAR ENDED DECEMBER 31, 1997
 
    REVENUES
 
    Total revenues increased $12.6 million, from $9.1 million for the year ended
December 31, 1997 to $21.7 million for the year ended December 31, 1998, an
increase of 139%. This increase was due primarily to increases in billable
services and in advertising and transaction fees.
 
    BILLABLE SERVICES.  Billable services revenues increased approximately $5.3
million, from $1.4 million for the year ended December 31, 1997 to $6.6 million
for the year ended December 31, 1998, an increase of 385%. This increase was due
primarily to the introduction of our billable subscription services, which
contributed $3.6 million in subscription fees in 1998; a short-term development
consulting contract which contributed $1.0 million; and technical support fees
associated with the growth of the subscriber base of Juno's free basic e-mail
service and of Juno Gold. At December 31, 1998, there were approximately 144,000
billable services subscribers, with approximately 53,000 subscribing to Juno
Gold and approximately 91,000 subscribing to Juno Web.
 
    ADVERTISING AND TRANSACTION FEES.  Advertising and transaction fees
increased $4.6 million, from $1.9 million for the year ended December 31, 1997
to $6.5 million for the year ended December 31, 1998, an increase of 244%. This
increase was due primarily to additional advertisers and advertisements
delivered, and the impact of additional strategic marketing alliances.
 
    From time to time, we engage in barter transactions in which we exchange
advertising with other Internet or traditional media companies, provide
advertising in exchange for software distribution services or other forms of
marketing assistance, or participate in other reciprocal service arrangements.
 
                                       36
<PAGE>
Barter transactions accounted for 0.3% of total advertising and transaction fees
for the year ended December 31, 1997, and 1.9% for the year ended December 31,
1998.
 
    DIRECT PRODUCT SALES.  Direct product sales increased $2.8 million, from
$5.8 million for the year ended December 31, 1997 to $8.6 million for the year
ended December 31, 1998, an increase of 47.0%. However, revenues from direct
product sales decreased $1.0 million, from $5.0 million for the six months ended
December 31, 1997 to $4.0 million for the six months ended December 31, 1998, a
decrease of 20.1%. This decline reflects our strategic decision during the first
quarter of 1998 to narrow the range of our direct product sales activities and
of the types of products offered to our subscribers. Instead, we decided to
concentrate on forming strategic marketing alliances and developing other uses
for our advertising inventory that we believe should generate revenues with
higher margins than direct products sales.
 
    COST OF REVENUES
 
    Total cost of revenues increased $8.5 million, from $8.5 million for the
year ended December 31, 1997 to $17.0 million, an increase of approximately
99.3%. This increase was due primarily to increases in costs associated with
billable services and with advertising and transaction fees.
 
    BILLABLE SERVICES.  Cost of revenues related to billable services increased
approximately $4.6 million, from $1.1 million for the year ended December 31,
1997 to $5.6 million for the year ended December 31, 1998, an increase of 433%.
This increase is primarily due to the costs of providing our billable
subscription services. Costs related to the provision of these billable
subscription services, principally customer service, technical support and
telecommunications expenses, accounted for 58.0% of the total costs of revenues
related to all billable services during 1998 and accounted for a majority of the
increase. Cost of revenues related to billable services as a percentage of total
billable services revenues increased from 76.8% for the year ended December 31,
1997 to 84.4% for the year ended December 31, 1998. This increase is principally
related to the introduction of billable subscription services, the relatively
high percentage of subscribers to these services who are in their initial
months, and the higher costs incurred in the early stages of a subscriber's life
cycle. We believe that customer service and technical support costs are
substantially higher in the initial months following signup than during later
months. We also incur significant startup costs associated with training
customer service and technical support representatives and with developing
processes necessary to support the subscriber base and its anticipated future
growth. We expect that, other things being equal, these costs will be highest as
a percentage of the related revenues during periods of rapid percentage growth
in the subscriber base of our billable subscription services.
 
    ADVERTISING AND TRANSACTION FEES.  Cost of revenues for advertising and
transaction fees increased approximately $2.1 million, from $1.7 million for the
year ended December 31, 1997 to $3.7 million for the year ended December 31,
1998, an increase of 125%. This increase was principally due to additional
advertisers and advertisements delivered and the impact of additional strategic
marketing alliances. The cost of revenues for advertising and transaction fees
as a percentage of advertising and transaction fees revenue decreased from 88.5%
for the year ended December 31, 1997 to 57.7% for the year ended December 31,
1998. This decrease is primarily due to economies of scale associated with
higher volumes of ad production, decreased telecommunications rates, faster
average connection speeds, and improvements in our production and distribution
methods.
 
    DIRECT PRODUCT SALES.  The cost of revenues for direct product sales
increased $1.8 million, from $5.8 million for the year ended December 31, 1997
to $7.6 million for the year ended December 31, 1998, an increase of 31.6%. This
increase corresponds to the increase in merchandise sold. The cost of revenues
for direct product sales as a percentage of direct product sales revenue
decreased from 99.2% for the year ended December 31, 1997 to 88.7% for the year
ended December 31, 1998. This decrease
 
                                       37
<PAGE>
was primarily due to efficiencies associated with outsourcing various functions
rather than performing them internally.
 
    OPERATING EXPENSES
 
    OPERATIONS, FREE SERVICE.  Expenses associated with operations, free service
decreased $1.7 million, from $11.1 million for the year ended December 31, 1997
to $9.4 million for the year ended December 31, 1998, a decrease of 15.3%. This
decrease was primarily due to declining telecommunications rates and increasing
connection speeds resulting from the use of faster modems by a portion of our
subscriber base. These cost savings were partially offset by an increase in the
number of subscribers connecting in a given month. During the month ended
December 31, 1997, 1,986,000 subscriber accounts connected and during the month
ended December 31, 1998, 2,434,000 subscriber accounts connected.
 
    SUBSCRIBER ACQUISITION.  Subscriber acquisition costs increased $2.2
million, from $3.1 million for the year ended December 31, 1997 to $5.3 million
for the year ended December 31, 1998, an increase of 69.9%. This increase is
primarily due to direct mail and advertising costs incurred to acquire
subscribers to our free basic e-mail service in the first half of 1998, ad
production and transmission costs associated with soliciting basic e-mail
subscribers to upgrade to our billable subscription services starting in July
1998, and costs incurred during the second half of 1998 to prepare for the
large-scale marketing activities planned for 1999. The increase in these costs
was partially offset by a decrease in expenses related to referral bounties as
various agreements that called for bounty payments expired or were terminated.
As a percentage of revenues, subscriber acquisition costs decreased from 34.5%
in 1997 to 24.6% in 1998. This percentage decrease was primarily due to the
relatively larger 1998 revenues. We expect that subscriber acquisition costs
will increase significantly both in absolute dollar terms and as a percentage of
total revenue in the future.
 
    SALES AND MARKETING.  Sales and marketing costs decreased $1.0 million, from
$12.6 million for the year ended December 31, 1997 to $11.6 million for the year
ended December 31, 1998, a decrease of 8.0%. This decrease is primarily due to
reductions in the level of trade advertising we undertook in 1998 as well as to
cost savings associated with our decisions to close our regional ad sales
offices and to narrow the range of our direct product sales activities. We
reduced the headcount assigned to our direct product sales activities, as well
as inventory risk, primarily by outsourcing substantially all of the
procurement, warehousing, fulfillment, billing and customer service aspects of
this initiative. In each of the first and second quarters of 1998, sales and
marketing expenses include charges of approximately $300,000 relating to
inventory write-offs, severance pay, and lease termination costs. As a
percentage of revenues, sales and marketing costs decreased from 139% in 1997 to
53.4% in 1998. This percentage decrease was primarily due to our relatively
larger 1998 revenues.
 
    PRODUCT DEVELOPMENT.  Product development costs increased approximately $2.5
million, from $4.9 million for the year ended December 31, 1997 to $7.3 million
for the year ended December 31, 1998, an increase of 51.1%. This increase is
primarily due to the costs associated with establishing development operations
in Hyderabad, India, a project we initiated in the fourth quarter of 1997.
Product development costs in 1998 related primarily to the continued development
of our billable subscription services and of various pieces of software. To
date, we have not capitalized expenses related to any software development
activities.
 
    GENERAL AND ADMINISTRATIVE. General and administrative costs decreased $0.1
million, from $2.9 million for the year ended December 31, 1997 to $2.8 million
for the year ended December 31, 1998, a decrease of 4.7%. This decrease is
primarily due to reduced personnel and related overhead costs, lower
professional fees, and cost containment programs. As a percentage of revenues,
general and administrative costs decreased from 31.9% for the year ended
December 31, 1997 to 12.7% for the year ended December 31, 1998. This decrease
was primarily due to the increase in revenues for the
 
                                       38
<PAGE>
year ended December 31, 1998. We expect that we will incur additional general
and administrative expenses as we hire additional personnel and incur additional
costs related to the growth of our business and our operation as a public
company, including directors' and officers' liability insurance, investor
relations programs and professional service fees. Accordingly, we anticipate
that general and administrative expenses will increase in absolute dollar terms
in the future.
 
    INTEREST INCOME, NET.  Interest income, net decreased $199,000, from
$243,000 for the year ended December 31, 1997 to $44,000 for the year ended
December 31, 1998, a decrease of 81.9%. This decrease is primarily due to
interest payments for borrowings and increased capital lease obligations,
partially offset by interest income earned on higher average cash balances
during 1998.
 
YEAR ENDED DECEMBER 31, 1997 COMPARED TO YEAR ENDED DECEMBER 31, 1996
 
    REVENUES
 
    Total revenues increased $9.0 million, from $0.1 million for the year ended
December 31, 1996 to $9.1 million for the year ended December 31, 1997. This
increase was primarily due to increases in direct product sales and in
advertising and transaction fees.
 
    BILLABLE SERVICES.  Billable services revenues increased $1.4 million, from
$6,000 for the year ended December 31, 1996 to $1.4 million for the year ended
December 31, 1997. This increase is primarily due to the implementation of
fee-based technical support for subscribers to our free basic e-mail service in
January 1997 and the initiation, as of March 1997, of our policy to charge
prospective subscribers to our free basic e-mail service a shipping and handling
fee if they request that a copy of our software be sent to them by mail.
 
    ADVERTISING AND TRANSACTION FEES.  Advertising and transaction fees
increased approximately $1.7 million, from $127,000 for the year ended December
31, 1996 to $1.9 million for the year ended December 31, 1997. This increase
reflects the expansion of our sales force and the growth in the subscriber base
of our free basic e-mail service to a level sufficient to interest advertisers,
and is principally due to the significantly higher number of advertisers and
advertisements delivered.
 
    DIRECT PRODUCT SALES.  Direct product sales increased $5.8 million, from
$3,000 for the year ended December 31, 1996 to $5.8 million for the year ended
December 31, 1997. This increase reflects the first full year of direct product
sales activity and the growth of our subscriber base.
 
    COST OF REVENUES
 
    Cost of revenues increased $8.2 million, from $0.3 million for the year
ended December 31, 1996 to $8.5 million for the year ended December 31, 1997.
This increase was primarily due to increases in costs associated with direct
product sales and with advertising and transaction fees.
 
    BILLABLE SERVICES.  The cost of revenues related to billable services
increased $1.1 million, from $0 for the year ended December 31, 1996 to $1.1
million in 1997. This increase is primarily due to costs associated with
providing fee-based technical support to subscribers to our free basic e-mail
service starting in January 1997 and with our policy to charge prospective
subscribers to our free basic e-mail service a shipping and handling fee if they
request that a copy of our software be sent to them by mail.
 
    ADVERTISING AND TRANSACTION FEES.  The cost of revenues for advertising and
transaction fees increased $1.4 million, from $278,000 for the year ended
December 31, 1996 to $1.7 million for the year ended December 31, 1997. This
increase is principally due to additional production and transmission costs
associated with the increase in advertisements delivered.
 
                                       39
<PAGE>
    DIRECT PRODUCT SALES.  The cost of revenues for direct product sales
increased $5.8 million, from $3,000 for the year ended December 31, 1996 to $5.8
million for the year ended December 31, 1997. This increase corresponds to the
increase in products sold.
 
    OPERATING EXPENSES
 
    OPERATIONS, FREE SERVICE.  The expenses associated with operations, free
service increased $5.3 million, from $5.8 million for the year ended December
31, 1996 to $11.1 million for the year ended December 31, 1997, an increase of
90.8%. This increase is primarily due to the growth in the subscriber base of
our free basic e-mail service, which resulted in increased telecommunications
and customer service costs, partially offset by declining telecommunication
rates and increasing average connection speeds. During the month ended December
31, 1996, 823,000 subscriber accounts connected and during the month ended
December 31, 1997, 1,986,000 subscriber accounts connected.
 
    SUBSCRIBER ACQUISITION.  Subscriber acquisition costs decreased $3.9
million, from $7.0 million for the year ended December 31, 1996 to $3.1 million
for the year ended December 31, 1997, a decrease of 55.1%. This decrease is
primarily due to the reduction in advertising and direct mail activities in 1997
relative to those in 1996, the year in which we launched our free basic e-mail
service. The effect of this reduction in advertising and direct mail activities
was partially offset by increased referral bounty expenses in 1997.
 
    SALES AND MARKETING.  Sales and marketing expenses increased $8.3 million,
from $4.3 million for the year ended December 31, 1996 to $12.6 million for the
year ended December 31, 1997, an increase of 195%. This increase is primarily
due to the growth of our advertising sales force as well as the expansion of our
direct product sales activities, which increased our expenses related to ad
production, ad transmission, and order fulfillment. These increases were
partially offset by reductions in the level of trade advertising we undertook in
1997.
 
    PRODUCT DEVELOPMENT.  Product development costs increased approximately $1.1
million, from $3.7 million for the year ended December 31, 1996 to $4.9 million
for the year ended December 31, 1997, an increase of 29.9%. This increase is
primarily due to increased personnel and related overhead costs, due to higher
headcount. Product development costs in 1997 related primarily to development of
refinements to our advertising and electronic commerce systems and certain other
pieces of software.
 
    GENERAL AND ADMINISTRATIVE.  General and administrative costs increased $0.7
million, from $2.2 million for the year ended December 31, 1996 to $2.9 million
for the year ended December 31, 1997, an increase of 33.4%. This increase is
primarily due to increased personnel and related overhead costs, due to
increased headcount.
 
    INTEREST INCOME, NET.  Interest income, net increased $115,000, from
$128,000 for the year ended December 31, 1996 to $243,000 for the year ended
December 31, 1997, an increase of 89.8%. This increase is primarily due to
interest income earned on higher average cash balances in 1997.
 
QUARTERLY RESULTS OF OPERATIONS DATA
 
    The following table sets forth unaudited quarterly statement of operations
data for each of the five quarters ended March 31, 1999, as well as the same
data expressed as a percentage of our total revenues for the periods indicated.
In our opinion, this unaudited information has been prepared substantially on
the same basis as the audited consolidated financial statements appearing
elsewhere in this prospectus, and all necessary adjustments, consisting only of
normal recurring adjustments, have been included in the amounts stated below to
present fairly the unaudited quarterly results of operations data. The quarterly
data should be read in conjunction with the consolidated financial statements
and the notes to these statements appearing elsewhere in this prospectus. The
operating results for any quarter are not necessarily indicative of the
operating results for any future period.
 
                                       40
<PAGE>
<TABLE>
<CAPTION>
                                                                          THREE MONTHS ENDED
                                                -----------------------------------------------------------------------
<S>                                             <C>           <C>            <C>            <C>           <C>
                                                  MAR. 31,                     SEPT. 30,      DEC. 31,
                                                    1998      JUNE 30, 1998      1998           1998      MAR. 31, 1999
                                                ------------  -------------  -------------  ------------  -------------
 
<CAPTION>
                                                                        (DOLLARS IN THOUSANDS)
<S>                                             <C>           <C>            <C>            <C>           <C>
STATEMENT OF OPERATIONS DATA:
Revenues:
  Billable services...........................   $      465     $     709      $   1,528     $    3,943     $   5,806
  Advertising and transaction fees............        1,228         1,540          1,759          1,927         2,265
  Direct product sales........................        2,577         2,035          1,847          2,136         1,649
                                                ------------  -------------  -------------  ------------  -------------
      Total revenues..........................        4,270         4,284          5,134          8,006         9,720
                                                ------------  -------------  -------------  ------------  -------------
Cost of revenues:
  Billable services...........................          387           580          1,306          3,333         4,678
  Advertising and transaction fees............          825           875            992          1,033         1,080
  Direct product sales........................        2,426         1,709          1,592          1,900         1,424
                                                ------------  -------------  -------------  ------------  -------------
      Total cost of revenues..................        3,638         3,164          3,890          6,266         7,182
                                                ------------  -------------  -------------  ------------  -------------
Operating expenses:
  Operations, free service....................        2,824         2,356          2,101          2,102         1,846
  Subscriber acquisition......................        1,453           427          1,067          2,387         2,700
  Sales and marketing.........................        4,270         2,884          2,212          2,218         2,312
  Product development.........................        1,835         1,630          1,849          2,031         1,854
  General and administrative..................          914           676            513            657           704
                                                ------------  -------------  -------------  ------------  -------------
      Total operating expenses................       11,296         7,973          7,742          9,395         9,416
                                                ------------  -------------  -------------  ------------  -------------
      Loss from operations....................      (10,664)       (6,853)        (6,498)        (7,655)       (6,878)
Interest income (expense), net................           74           (14)             6            (22)          111
                                                ------------  -------------  -------------  ------------  -------------
      Net loss................................   $  (10,590)    $  (6,867)     $  (6,492)    $   (7,677)    $  (6,767)
                                                ------------  -------------  -------------  ------------  -------------
                                                ------------  -------------  -------------  ------------  -------------
 
PERCENTAGE OF REVENUES:
  Revenues:
    Billable services.........................         10.9%         16.6%          29.7%          49.3%         59.7%
    Advertising and transaction fees..........         28.8          35.9           34.3           24.1          23.3
    Direct product sales......................         60.3          47.5           36.0           26.6          17.0
                                                ------------  -------------  -------------  ------------  -------------
      Total revenues..........................        100.0         100.0          100.0          100.0         100.0
                                                ------------  -------------  -------------  ------------  -------------
  Cost of revenues:
    Billable services.........................          9.1          13.5           25.4           41.7          48.1
    Advertising and transaction fees..........         19.3          20.4           19.4           12.9          11.1
    Direct product sales......................         56.8          40.0           31.0           23.7          14.7
                                                ------------  -------------  -------------  ------------  -------------
      Total cost of revenues..................         85.2          73.9           75.8           78.3          73.9
                                                ------------  -------------  -------------  ------------  -------------
  Operating expenses:
    Operations, free service..................         66.1          55.0           40.9           26.2          19.0
    Subscriber acquisition....................         34.0          10.0           20.7           29.8          27.8
    Sales and marketing.......................        100.0          67.3           43.1           27.7          23.8
    Product development.......................         43.0          38.0           36.0           25.4          19.1
    General and administrative................         21.4          15.8           10.1            8.2           7.2
                                                ------------  -------------  -------------  ------------  -------------
      Total operating expenses................        264.5         186.1          150.8          117.3          96.9
                                                ------------  -------------  -------------  ------------  -------------
      Loss from operations....................       (249.7)       (160.0)        (126.6)         (95.6)        (70.8)
  Interest income (expense), net..............          1.7          (0.3)           0.1           (0.3)          1.2
                                                ------------  -------------  -------------  ------------  -------------
      Net loss................................       (248.0)%      (160.3)%       (126.5)%        (95.9)%       (69.6)%
                                                ------------  -------------  -------------  ------------  -------------
                                                ------------  -------------  -------------  ------------  -------------
</TABLE>
 
                                       41
<PAGE>
    The following table sets forth selected subscriber data for each of the five
quarters ended March 31, 1999. This data should be read in conjunction with the
information appearing elsewhere in this prospectus. The selected subscriber data
for any quarter are not necessarily indicative of future periods.
 
<TABLE>
<CAPTION>
                                                                          SEPT. 30,      DEC. 31,      MAR. 31,
SELECTED SUBSCRIBER DATA:                MAR. 31, 1998   JUNE 30, 1998      1998           1998          1999
- ---------------------------------------  --------------  -------------  -------------  ------------  ------------
<S>                                      <C>             <C>            <C>            <C>           <C>
Total subscriber accounts as of (1)....      4,699,000      5,298,000      5,852,000     6,336,000     6,817,000
  Subscriber accounts that connected in
    the three-month period ended.......      2,924,000      3,032,000      3,121,000     3,108,000     3,108,000
  Subscriber accounts that connected in
    the month ended....................      2,340,000      2,361,000      2,409,000     2,434,000     2,438,000
  Average subscriber accounts that
    connected per day in the month
    ended..............................        889,000        836,000        889,000       887,000       912,000
Billable subscription service accounts
  as of (2)............................             --             --         64,000       144,000       207,000
</TABLE>
 
- ------------------------
 
(1) Includes all user accounts created since Juno's inception, regardless of
    activity level, if any, net of accounts that have been cancelled.
 
(2) Billable subscription service accounts are a subset of total subscriber
    accounts and, to the extent applicable, are also included in the number of
    subscriber accounts shown as having connected during the periods described.
 
    We have historically experienced seasonality, with use of Internet services
being somewhat lower during the summer and year-end holiday periods. We believe
seasonality favorably impacts subscriber acquisition during the first and fourth
calendar quarters. We further believe that seasonality may negatively affect our
advertising revenue during the first and third calendar quarters. Finally, we
believe that direct product sales are positively affected in the fourth quarter
due to the year-end holiday buying season, although we cannot assure you that
this trend will continue in future periods. See "Risk Factors--Juno's business
is subject to fluctuations in operating results which may negatively impact the
price of our stock."
 
    Despite the impact of seasonality, our revenues have increased in all
quarters presented. We believe that these increases occurred for a number of
reasons, including:
 
    - the overall growth of our business and the industry's growth as a whole;
 
    - the launch of our billable subscription services on July 22, 1998; and
 
    - the increase in advertising and transaction fees generated by strategic
      marketing alliances beginning with the third quarter of 1998.
 
We cannot assure you that we will not experience seasonal fluctuations and the
risks associated therewith in the future. Primarily due to our previously
described strategic decision to narrow our direct product sales activities,
direct product sales revenue decreased in all quarters except for the fourth
quarter, which we believe was positively affected by the holiday buying season.
 
    Cost of revenues increased as a percentage of total revenues in the third
and fourth quarters of 1998 primarily due to:
 
    - the startup costs associated with the introduction of billable
      subscription services;
 
    - the relatively high percentage of subscribers to these services who are in
      their initial months;
 
                                       42
<PAGE>
    - the higher costs incurred in the early months of a subscriber's life
      cycle; and
 
    - the fact that most Juno Web subscribers currently receive their first
      month of service at no charge.
 
    Cost of revenues decreased, as a percentage of total revenues, from 78.3%
for the three months ended December 31, 1998 to 73.9% for the three months ended
March 31, 1999. This decrease was primarily due to the decline in the percentage
of billable subscription service users who were in their initial months
following signup, as compared to previous quarters. In addition, the cost of
revenues, as a percentage of total revenues, was positively impacted by a
contribution from revenue recognized over the shortened life of a strategic
marketing alliance that featured a minimum revenue guarantee.
 
    Operating expenses decreased in the second quarter of 1998 due to reduced
subscriber acquisition activities, and in the second and third quarters of 1998
due to savings resulting from the narrowing of our direct product sales
activities, the closing of regional sales offices, and cost containment
programs. Operating expenses increased in the fourth quarter of 1998 principally
because of increased spending initiated during the third quarter related to
subscriber acquisition. This increase in spending reflects increased levels of
marketing conducted over the Juno service in order to promote our billable
subscription services to our free basic e-mail service subscribers, as well as
preparations for the large-scale marketing activities planned for 1999. The
increase in subscriber acquisition costs continued in the three months ended
March 31, 1999. Total operating costs remained relatively flat as compared to
the three months ended December 31, 1998 primarily due to lower costs associated
with operating the free basic e-mail service. The cost of operations, free
service decreased due to the continued decline in telecommunications rates and
increases in connection speeds resulting from the use of faster modems by a
portion of our subscriber base. We anticipate significant increases in
subscriber acquisition expenses. See "Use of Proceeds." We anticipate that this
increased spending will result in substantial fluctuations in subscriber
acquisition expenses, operating expenses, and net loss on a quarter-to-quarter
basis.
 
LIQUIDITY AND CAPITAL RESOURCES
 
    Prior to the March 1999 private placement described below, we were financed
primarily through capital contributions from entities or persons affiliated with
D. E. Shaw & Co., Inc. In March 1998, we borrowed $10.0 million from D. E. Shaw
Securities Group, L.P., an affiliated party, pursuant to an unsecured note. The
note bears interest at the Federal Funds rate plus 0.375%, which totalled 5.355%
as of March 31, 1999. Outstanding principal and any accrued but unpaid interest
is required to be paid upon the earlier of December 31, 2000 and the date of
completion of an initial public offering by Juno registered under the Securities
Act of 1933, and will be repaid in full with the proceeds from this offering and
is otherwise scheduled to mature on December 31, 2000. At March 31, 1999, the
balance, including accrued interest, of the note was $8.8 million. See "Use of
Proceeds."
 
    For the three months ended March 31, 1999, we used $6.2 million in cash for
working capital purposes and to fund losses from operations. In addition, we
paid $10.0 million for advertising that may be used at any time prior to March
2001, bringing total net cash used in operating activities to $16.2 million. Net
cash used in operating activities was $16.4 million, $33.6 million and $20.9
million for the years ended December 31, 1996, 1997 and 1998, respectively. The
decrease in net cash used in operating activities of $12.7 million from $33.6
million for the year ended December 31, 1997 to $20.9 million for the year ended
December 31, 1998 was primarily the result of deferred revenues, changes in
working capital accounts, and non-cash charges for depreciation and
amortization.
 
    Net cash used in investing activities was $0.2 million for the three months
ended March 31, 1999. Net cash used in investing activities was $0, $3.4 million
and $1.6 million for the years ended December 31, 1996, 1997 and 1998,
respectively. The principal use of cash for the periods presented was for the
purchase of fixed assets. Prior to July 1997, we utilized fixed assets owned by
DESCO, L.P.,
 
                                       43
<PAGE>
the expense relating to which was allocated to us. Beginning in July 1997,
substantially all new acquisitions of fixed assets have been made directly by
us.
 
    Net cash provided by financing activities was $61.4 million for the three
months ended March 31, 1999. In March 1999, we received net proceeds of $61.8
million in exchange for our issuance of 10,138,716 shares of Series B redeemable
convertible preferred stock, which will automatically convert into an equivalent
number of shares of common stock upon the closing of this offering. Net cash
provided by financing activities was $17.0 million, $50.1 million and $16.9
million for the years ended December 31, 1996, 1997 and 1998, respectively.
Financing activities are primarily capital contributions, the borrowings and
repayments under the note during 1998, and capital lease obligation payments.
 
    We do not currently have any material commitments for capital expenditures
outside of the normal course of business and recent historical trends. However,
we do anticipate that we will increase our capital expenditures and lease
commitments beyond recent historical trends to expand our infrastructure in
anticipation of the growth of our subscriber base. We may also take advantage of
opportunities to employ various cost-effective but capital-intensive approaches
to the provision of our Internet services. As a result of our outsourcing
arrangements for telecommunications services and customer service, we have
substantially reduced the level of capital expenditures that would otherwise
have been necessary to develop our product offerings. In the event that these
outsourcing arrangements were no longer available to us, significant capital
expenditures would be required and our business and financial results could
suffer. In addition, we anticipate significantly increasing subscriber
acquisition expenses in order to fund subscriber growth and help us gain market
share. Additional expenditures in connection with subscriber acquisition will
represent a material use of our cash resources.
 
    We believe that the net proceeds of this offering, together with our
existing cash and cash equivalents, will be sufficient to meet our anticipated
cash needs for at least the next twelve months. If cash generated from
operations is insufficient to satisfy our liquidity requirements, we may seek to
sell additional equity or debt securities or to obtain a credit facility. The
sale of additional equity or convertible debt securities would result in
additional dilution to our stockholders. The incurrence of indebtedness would
result in increased fixed obligations and could result in covenants that would
restrict our operations. We have not made arrangements to obtain additional
financing and there can be no assurance that financing will be available in
amounts or on terms acceptable to us, if at all. See "Risk Factors--We cannot
predict our future capital needs and we may not be able to secure additional
financing."
 
IMPACT OF THE YEAR 2000
 
    The Year 2000 issue is the result of computer programs being written using
two digits rather than four to identify a given year. Many of the computer
programs that Juno utilizes include specialized functions that involve date
manipulation. These functions are critical to our business, and include:
 
    - signup of new subscribers to our services;
 
    - validation of credit cards;
 
    - transfer, storage and processing of e-mail and advertisements;
 
    - scheduling of advertisements and reporting of results to advertisers; and
 
    - billing and invoicing of advertisers and subscribers to our billable
      subscription services.
 
    Juno's business is heavily dependent upon the use of operating systems and
applications that, in the aggregate, involve millions of lines of computer code.
Similarly, our business is also dependent on the coordinated functioning of a
network made up of hundreds of servers and other pieces of computer equipment,
all of which have computer code embedded in them. If any of the programs that
Juno utilizes misinterpret the date code "00" as the year 1900 rather than the
year 2000, significant errors
 
                                       44
<PAGE>
could be introduced into the information we use to manage the business and the
computer systems that operate our online services. These miscalculations could
result in errors in our operations or in disruption of operations, including,
among other things, a temporary inability to process transactions, send invoices
or engage in other normal business activities.
 
    STATE OF READINESS.  We have begun to assess the Year 2000 readiness of our
information technology systems. Our overall Year 2000 readiness plan consists of
the following phases:
 
    - preparing an inventory of all software and hardware items affected by the
      Year 2000 issue;
 
    - testing our internally developed proprietary software for quality
      assurance;
 
    - contacting providers of material information technology and other
      technology;
 
    - repairing or replacing components that are determined to not be Year 2000
      compliant; and
 
    - creating contingency plans to address potential Year 2000 failures that we
      cannot control or have not previously been able to detect or repair.
 
    Specific steps in our Year 2000 assessment to date have included:
 
    - running several successful Year 2000 simulations on our test systems to
      verify software performance by artificially moving the date forward from
      December 31, 1999 to January 1, 2000;
 
    - reviewing source code of our proprietary software to identify all
      functions that process dates; and
 
    - identifying critical suppliers and communicating with them about their
      plans and progress in addressing any Year 2000 problems they may face.
 
    The Year 2000 readiness plan described above is being carried out across the
four critical areas where we believe the Year 2000 problem might affect our
business:
 
    - Juno product software, which consists of all software directly used by
      subscribers in connection with our free basic e-mail service and/or our
      billable subscription services;
 
    - Juno product hardware, which consists of the hardware that we use directly
      in connection with our free basic e-mail service and/or our billable
      subscription services;
 
    - infrastructure, which consists of hardware and software used by our staff
      in the course of operating our business other than Juno product hardware
      and software; and
 
    - external agents, which includes all other hardware, software, services and
      related systems provided by third parties and on which we rely.
 
                                       45
<PAGE>
    The following table sets forth our progress and completion targets in
assessing our Year 2000 readiness in these four critical areas. In each case our
remaining assessment and repair is significantly dependent upon the Year 2000
compliance of our suppliers and vendors.
 
<TABLE>
<CAPTION>
                                                 INVENTORY               ASSESSMENT          REPAIR/REPLACEMENT
                                           ----------------------  ----------------------  ----------------------
<S>                                        <C>                     <C>                     <C>
 
Product Software.........................  100% complete           75% complete
                                                                   Completion target:      Completion target:
                                                                   August 31, 1999         September 30, 1999
 
Product Hardware.........................  90% complete            80% complete
                                           Completion target:      Completion target:      Completion target:
                                           July 31, 1999           September 30, 1999      November 30, 1999
 
Infrastructure...........................  90% complete            70% complete
                                           Completion target:      Completion target:      Completion target:
                                           July 31, 1999           September 30, 1999      November 30, 1999
 
External Agents..........................  80% complete            30% complete
                                           Completion target:      Completion target:      Completion target:
                                           July 31, 1999           October 31, 1999        December 15, 1999
</TABLE>
 
    To address the results of our assessment to date, we have:
 
    - enhanced several parts of our software to permit the entry of four-digit
      years rather than two-digit years;
 
    - converted all dates within our databases to four-digit years;
 
    - upgraded some of our operating systems and applications to versions
      recommended by our vendors in order to achieve Year 2000 compliance of
      these components; and
 
    - identified, prioritized and contacted third party vendors who provide us
      with key services including telecommunication services and customer
      service, requiring them to provide assurances of their Year 2000
      compliance.
 
    We plan to continue this Year 2000 assessment and repair process during the
remainder of 1999 with the intention of:
 
    - monitoring our vendors' progress in their own Year 2000 assessment and
      repair;
 
    - scheduling tests to determine the ability of our systems to work with
      those of our service providers; and
 
    - reviewing non-information technology systems and embedded systems which,
      if not Year 2000 compliant, could affect our business.
 
    COSTS.  To date, we have not incurred any material costs in identifying or
evaluating Year 2000 compliance issues. The cost of software tools and
consulting expenses used for detection of Year 2000 problems is not currently
expected to exceed $100,000. We expect that our existing employees or
consultants will perform all significant work for the Year 2000 project
described above. We do not anticipate hiring any additional employees or
incurring any significant consulting expenses for the Year 2000 project. To
date, no other significant information technology projects have been deferred
due to our Year 2000 efforts.
 
    RISKS.  We are not currently aware of any significant Year 2000 compliance
problems relating to our proprietary software, our information technology
systems or our other systems that would materially harm our business, results of
operations or financial condition. During our remaining assessment, we may
discover Year 2000 compliance problems in our proprietary software that may
 
                                       46
<PAGE>
require substantial repair or replacement. If problems are discovered in
versions of our product software that are already in use by our subscribers, we
may need to distribute new versions of the software to those subscribers. It may
not be possible to correct these problems in a timely manner.
 
    Material third-party software, hardware, service providers or
non-information-technology infrastructure may contain Year 2000 compliance
problems that require substantial repair and/or replacement, which could be
time-consuming and expensive. It may not be possible to repair or replace some
of these components or service providers in a timely manner.
 
    The failure to correct any material Year 2000 problem could materially harm
our business, results of operations and financial condition because:
 
    - new subscribers may be unable to sign up for our services, resulting in
      reduced growth and lower effectiveness of our marketing efforts;
 
    - current subscribers may be unable to upgrade to higher service levels,
      resulting in reduced revenue growth and lower effectiveness of our
      marketing efforts;
 
    - current subscribers may be unable to use our services or get adequate
      customer support, which may result in increased attrition, higher customer
      support costs and reduced revenue; and/or
 
    - we may be subject to claims of mismanagement, misrepresentation or breach
      of contract and related litigation, which could be costly and
      time-consuming to defend and, if defended unsuccessfully, could result in
      the imposition of substantial fines or judgments.
 
    In addition, we cannot assure you that governmental agencies, utility
companies, Internet access companies, third-party service providers and others
outside our control will be Year 2000 compliant. The failure by these entities
to be Year 2000 compliant could result in a systemic failure beyond our control,
including, for example, a prolonged failure of Internet, telecommunications
and/or electrical systems, which could also prevent us from providing our
services, or prevent users from accessing our services, either of which would
materially harm our business, results of operations and financial condition.
 
    CONTINGENCY PLANS.  We are still engaged in an ongoing Year 2000 assessment
and have not yet developed any contingency plans. Contingency planning will be
conducted as our ongoing assessment and as feedback received from third parties
necessitates.
 
IMPACT OF RECENTLY ISSUED ACCOUNTING STANDARDS
 
    In June 1998, the Financial Accounting Standards Board, or FASB, issued
Statement of Financial Accounting Standards No. 133, "Accounting for Derivative
Instruments and Hedging Activities." Statement 133 establishes new accounting
and reporting standards for derivative financial instruments and for hedging
activities. As of December 31, 1998, Juno had no derivative instruments.
 
    In June 1997, FASB issued Statement No. 131 "Disclosures about Segments of
an Enterprise and Related Information." Statement 131 establishes standards for
the way that public business enterprises report information about operating
segments in annual financial statements and requires that those enterprises
report selected information about operating segments in interim financial
reports issued. The statement has not had an impact on Juno's financial
statement disclosures as its financial statements reflect how the "key operating
decision makers" view the business. Accordingly, the financial statements are
presented as a single segment.
 
    In June 1997, FASB issued Statement No. 130, "Reporting Comprehensive
Income." Statement 130 establishes standards for the reporting and display of
comprehensive income and its components in the financial statements. Statement
130 is effective for years beginning after December 15, 1997. The
 
                                       47
<PAGE>
statement has not had an impact on Juno's financial statements as Juno has no
other comprehensive income to report.
 
   
    In February 1997, FASB issued Statement No. 128 "Earnings Per Share."
Statement 128 replaced primary and fully diluted earnings per share with basic
and diluted earnings per share. The statement makes modifications to the
earnings per share calculations defined in the Accounting Principles Board
Opinion No. 15 "Earnings Per Share." Statement 128 is effective for years ending
after December 31, 1997. Juno has adopted Statement 128.
    
 
    In March 1998, the American Institute of Certified Public Accountants issued
Statement of Position 98-1 "Accounting for the Costs of Computer Software
Developed or Obtained for Internal Use" which provides guidance on accounting
for the costs of computer software developed or obtained for internal use. The
pronouncement identifies the characteristics of internal use software and
provides guidance on new cost recognition principles. Statement 98-1 is
effective for financial statements for fiscal years beginning after December 15,
1998. The adoption of Statement 98-1 will not have a significant impact on
Juno's consolidated financial position, results of operations and cash flows.
 
                                       48
<PAGE>
                                    BUSINESS
 
OUR COMPANY
 
    Juno Online Services, Inc. is a leading provider of Internet-related
services to millions of computer users throughout the United States. We offer
several levels of service, ranging from basic dial-up Internet e-mail--which is
provided to the end user for free--to full, competitively priced access to the
Web. Our strategy of offering several different service levels and our
easy-to-use, intuitive software are designed to attract a broad spectrum of
users, including those who are interested only in e-mail, those who initially
begin with e-mail but over time develop a need for Web access, and those who
seek full Web access from the outset.
 
    Our services are provided nationwide through over 1,900 local telephone
numbers, which we lease from several providers. These phone numbers can be
reached by the vast majority of the U.S. population without having to place a
long distance telephone call. Our revenues are derived primarily from the
subscription fees we charge for the use of our more advanced service levels,
from the sale of advertising, and from the direct sale of products to our
subscribers.
 
    Since our inception in 1995, we have pursued a two-phase business strategy.
The initial phase of this strategy focused on building computer systems and
related infrastructure that could be rapidly expanded to accommodate an
increasing number of users, and on maximizing the number of subscribers to our
free basic e-mail service. We chose to focus on e-mail because it is one of the
most popular activities on the Internet, and because we believed that offering
basic e-mail service for free would allow us to rapidly and cost-effectively
build a large user base from which we might then expect to derive various forms
of revenue. In particular, we planned to draw on our ability to communicate
inexpensively with our user base in order to pursue revenues derived from the
sale of advertising and the direct marketing of products to our subscribers and
to offer our basic e-mail users the opportunity to purchase more advanced
services including full Web access. We believed our basic e-mail users would be
more likely to purchase these services from us than from a competing service
provider due to their expected aversion to the process of switching e-mail
addresses. We further believed the economics of this approach would be enhanced
by technology we had developed that allowed us to take advantage of a
substantial number of hours of consumer contact while paying for a much smaller
number of hours during which customers were actually connected by telephone to
our central computers.
 
    In July 1998, we commenced the second phase of our business strategy by
introducing two additional service levels: an enhanced e-mail service and a full
Web access service. Unlike our basic e-mail service, which is free, these
service offerings are billed at either a flat rate or a combination of a reduced
flat rate plus hourly usage fees. These services utilize the same easy-to-use
software as our basic e-mail service, and users of the current version of our
software are able to easily upgrade to our billable subscription services by
clicking on clearly labeled buttons within this environment. JUNO GOLD, the
enhanced e-mail service, supplements our basic e-mail service by allowing users
to send and receive non-text files such as pictures, spreadsheets and word
processor documents. JUNO WEB provides full Internet access utilizing a standard
Web browser of the user's choice. The home page on which all Juno users begin
each Web session is operated under an agreement with Lycos, one of the
Internet's leading "portal" sites, that provides us with a portion of any
associated advertising revenues.
 
    Our services have been very popular, with more than 6.8 million Juno
accounts created since the launch of the basic e-mail service in April 1996.
During the month of March 1999, an average of 912,000 user accounts dialed into
our service on any given day, with a total of 2.4 million user accounts
connecting during the full month of March, and 3.1 million user accounts
connecting during the three-month period ended March 31, 1999. We launched our
billable subscription services on July 22, 1998, and as of March 31, 1999, we
had approximately 207,000 billable service subscribers, consisting of
approximately 86,000 Juno Gold subscribers and approximately 121,000 Juno Web
subscribers. We have initially marketed Juno Gold and Juno Web only to our own
free e-mail subscribers. We intend,
 
                                       49
<PAGE>
however, to begin marketing these services beyond the existing Juno user base
through a substantial external marketing campaign beginning in the second
quarter of 1999.
 
   
    In addition to fees payable by subscribers to our billable subscription
services, we derive revenues from the sale of advertising. As of March 31, 1999,
approximately 200 firms had advertised on the Juno services. Additionally, we
have entered into a number of major strategic marketing alliances, including
several that involve multi-million-dollar guaranteed minimum payments to Juno.
Our strategic marketing alliances include multi-year relationships with First
USA, Qwest, and The Hartford, as well as a one-year agreement with AT&T Wireless
Services.
    
 
    In servicing the needs of advertisers and marketing partners, we benefit
from the high degree to which custom-tailored advertisements can be selectively
targeted to various segments of our subscriber base. Juno ads can be targeted
based not only on geography and patterns of computer use, as is often possible
in the case of Web site advertising as well, but also according to such
characteristics as age, gender, income, expected major purchases in any of 20
specified categories, hobbies, interests, family size, and/or educational
attainment. This data is obtained from the detailed "Member Profile" survey that
all subscribers to our basic e-mail service are required to complete at the time
they create their accounts.
 
MARKET OPPORTUNITY
 
    The Internet is becoming an increasingly significant global medium for
communications, advertising, and commerce. International Data Corporation
estimates that more than 56 million individuals in the U.S. used the Internet in
1998, and projects that this figure will reach 136 million by the year 2002. We
expect that these increases will have a significant impact on the three main
service and product sectors in which Juno currently operates.
 
    BILLABLE SUBSCRIPTION SERVICES REVENUES.  IDC projects that
consumer-targeted dial-up Internet access revenues in the U.S. will grow from
$4.7 billion in 1998 to $10.6 billion in 2002.
 
    ADVERTISING REVENUES.  Jupiter Communications has projected that online
advertising expenditures will grow from an estimated $1.9 billion in 1998 to
$7.7 billion in 2002.
 
   
    DIRECT PRODUCT SALES.  We believe, based on estimates and projections from
an independent third party Internet research firm, that online sales for retail
goods other than automobiles totaled $4.8 billion in 1998, and that those sales
will increase to $50.2 billion in 2002.
    
 
OUR SERVICES
 
    Our services and software have been designed with special attention to the
needs of consumers who are just now beginning to explore the Internet. The needs
and preferences of this large and rapidly growing body of new Internet users are
likely to differ significantly from those of technically sophisticated early
Internet users and computer hobbyists. We believe the success of our design is
reflected in studies indicating that ease of use is among the characteristics
most closely associated with Juno, and in the relatively high rate at which
members pass along copies of the Juno software to others.
 
    In addition, we believe that Juno is unique among major online services in
offering consumers a gradual migration path onto the Internet. Subscribers who
are not yet ready to use or pay for the full capabilities of the Internet can
begin their use of the Internet with our basic e-mail service or with Juno Gold,
then migrate to Juno Web once they are ready to do so.
 
                                       50
<PAGE>
    BASIC E-MAIL SERVICE
 
    Our basic e-mail service provides subscribers with the ability to send and
receive text-only e-mail over the Internet for free. Unlike Web-based e-mail
services, such as Microsoft's Hotmail, our basic service does not require the
user to have previously subscribed for access to the Web, and unlike subscribers
to most other major online services or Internet access providers, our
subscribers currently pay us no fees of any sort for the use of our basic
service.
 
    We have expended significant effort to make our basic e-mail service easy to
use. Our fundamental design goal has been to create software that novice users
can understand at a glance, but which will continue to satisfy subscribers once
they have gained more experience. In addition to the basic e-mail
functions--sending, receiving, forwarding, printing, and replying to messages,
for example--we also offer a full-function address book, customizable mailing
lists, folders for storing mail, and a built-in spell-check feature, all within
a simple and visually attractive point-and-click environment.
 
    After receiving a copy of our software, a new subscriber follows simple,
clearly worded on-screen instructions to install Juno on his or her computer,
and to select an e-mail address and password. In addition, in order to create a
free e-mail account, each subscriber to our free e-mail service must complete
the Member Profile survey, providing information that can be used for the
selective targeting of advertising.
 
    JUNO GOLD
 
    Juno Gold augments the capabilities of Juno's basic e-mail service by
providing subscribers with the ability to send and receive non-textual computer
files such as word processor documents, spreadsheets, photographs, artwork,
electronic greeting cards, audio and video files, and computer programs by
"attaching" them to e-mail messages. Subscribers who wish to send a file
attachment simply click on the "Attach File" button on the "Write" screen of the
Juno interface and choose the appropriate file from the list of files that
appears. Subscribers who receive an e-mail message containing a file attachment
can view the contents of that attachment by double-clicking on an icon that
appears inside the message on the "Read" screen of the Juno interface.
 
    Juno Gold is presently offered at a list price of $2.95 per month, billed
annually in advance. Juno Gold subscribers also have the option of signing up
for a plan that permits them to use the Web at a rate of $2.95 per hour of Web
usage, with no monthly minimum.
 
    JUNO WEB
 
    Juno Web provides subscribers with the ability to explore the Web using
either Microsoft's Internet Explorer or Netscape's Navigator as their browser.
Users who wish to visit the Web can do so at any time during a Juno session by
clicking on the prominent "Web" tab on the main Juno interface, and may return
to reading or writing e-mail at any time by clicking on Juno's "Read" or "Write"
tabs. When Juno Web subscribers begin a Web session, the first Web pages they
see provide them with a broad set of tools and content to help them understand,
navigate, and use the Web. Most of the content, directory functionality, and
Internet search functions associated with this Web page are currently provided
by Lycos, one of the Internet's leading "portal" sites. In return for directing
visitors to a co-branded version of this portal site, we receive guaranteed
per-visit fees from Lycos as an advance against a share of any revenue Lycos
generates through the sale of advertisements on the various Web pages comprising
this co-branded portal site. We also intend to begin offering Juno Web
subscribers additional Web features such as home page personalization, instant
messaging, and news and information services, either through our current
agreement with Lycos or through alternate arrangements.
 
                                       51
<PAGE>
    In addition to Web access, Juno Web provides subscribers with all of the
features included in Juno Gold. Each higher level of Juno service thus offers
all of the features provided at any lower service level in addition to the
incremental capabilities associated with that particular service level.
 
    Juno Web is currently marketed at a list price of $19.95 per month for a
flat-rate plan or $9.95 per month for up to seven hours of metered usage with
additional usage billed at a rate of $1.95 per hour. We have also begun testing
a variety of promotional offerings that provide periods of discounted or free
access in order to determine their impact on conversion and retention rates, and
we may experiment with other pricing plans for both services in the future.
 
    OTHER BILLABLE SERVICES
 
    In addition to Juno Gold and Juno Web, we offer other billable services,
including billable technical support for subscribers to our free basic e-mail
service or to Juno Gold, and currently provide consulting services under a
short-term contract with a third party.
 
OUR STRATEGY
 
    Our principal objective is to strengthen our position as a leading provider
of consumer Internet-related services by capturing an increasing number of hours
of customer contact, and by expanding our billable subscription service
offerings, advertising sales, strategic marketing relationships, and electronic
commerce activities. In particular, we plan to:
 
    RAPIDLY EXPAND OUR OVERALL SUBSCRIBER BASE.  Our services are targeted to
meet the needs of consumers with little or no computer experience, who we
believe are seeking access to the Internet in increasing numbers. We intend to
make these consumers aware of our services and to rapidly expand our subscriber
base through a significant expansion of our marketing activities. These
activities may include television, radio, magazine, and newspaper advertising;
direct mail and telemarketing campaigns; the distribution of our software along
with personal computers and other technology products; paid Web advertising; the
bartering of advertising on the Juno system for advertising on various Web sites
and in other online and conventional media; various incentives for referrals by
current subscribers; and/or the acquisition of other Internet access providers.
In addition, we may consider various alternatives for international expansion.
 
    MIGRATE SUBSCRIBERS TO HIGHER LEVELS OF SERVICE.  Our software is designed
to allow users to easily move to higher levels of service when they are ready to
use and pay for them through the point-and-click activation of additional
features, and to do so without having to change e-mail addresses. We plan to
continue marketing our higher service levels to our existing subscriber base
through a variety of advertising messages and promotions delivered through the
Juno ad system. Because internal marketing of this sort is generally less
expensive for us on a per-subscriber basis than subscriber acquisition efforts
conducted through direct mail or most other external advertising channels, we
believe the upward migration of our free basic e-mail subscribers should reduce
average subscriber acquisition costs for our billable subscription services. We
may also offer additional services or service levels to meet the needs of our
users, or may restructure or change the nature or pricing of our various service
levels at some point in the future.
 
    LEVERAGE AND EXPAND OUR STRATEGIC MARKETING ALLIANCES AND ADVERTISING
SALES.  We plan to maintain our focus on initiating new strategic marketing
alliances and expanding the size and scope of our existing alliances. We believe
there may be significant opportunities to expand the scope of our relationships
with some of our existing alliance partners, which currently include AT&T
Wireless Services, First USA, Qwest and The Hartford. In addition, we believe it
may be possible to execute new category-exclusive strategic alliances with major
firms in other industries. Finally, to the extent we are able to increase the
size of our subscriber base, we believe this expansion could increase the value
of our existing strategic marketing and advertising relationships and our
ability to form similar relationships with other firms on favorable terms.
 
                                       52
<PAGE>
    EMBRACE NEW TECHNOLOGIES WHILE MAINTAINING TECHNOLOGY INDEPENDENCE.  We
currently use several wholesalers of telecommunications services to connect our
subscribers to Juno's central computers and to the Web. Although we may at some
point consider investing in various forms of networking
infrastructure--particularly in cases where a given type of access would
otherwise be difficult or prohibitively costly to obtain--we currently expect to
continue our extensive use of these wholesale providers. We believe this
strategy will enable us to remain network-independent, and to switch providers
or technologies as cost and/or performance improvements become available. As a
result, we believe we can be flexible in responding to subscriber demand for
higher-speed access and other types of improved service. In particular, as
digital subscriber line technology, commonly known as DSL, cable modems,
high-speed wireless access, and/or other broadband technologies begin to
transform the Internet access landscape, we intend to embrace one or more of
these technologies in order to provide high-bandwidth services to our
subscribers in the most cost-effective manner then available to us.
 
TECHNOLOGY AND INFRASTRUCTURE
 
    The operation of our services is supported by computer systems and related
infrastructure that have successfully sustained high levels of usage and of
growth. Since the launch of our first service, our systems have processed and
delivered more than two billion e-mail messages. Our servers routinely handle
more than two million user connections per day and more than five million e-mail
messages per day. Our members have not suffered the sorts of repeated, prolonged
system-wide outages that have reportedly affected other online services. To
enable our computer and telecommunications facilities to keep pace with the
rapid growth of our subscriber base, we have made a concerted effort to design
our systems architecture to be highly flexible, to grow quickly without
sacrificing reliability, and to handle problems quickly when they arise.
 
    To use our services, subscribers initiate telephone connections between
their personal computers and computer hardware in local or regional facilities
known as points of presence. We contract for the use of points of presence
around the country from various telecommunications carriers, including MCI
WorldCom, through its UUNET Technologies and MCI WorldCom Advanced Networks
divisions; Concentric Network Corporation; and Sprint Communications Company.
These telecommunications companies also carry their data between the points of
presence and our central computers, which are located in Cambridge,
Massachusetts and Jersey City, New Jersey. We currently have lease commitments
for the use of over 1,900 local telephone numbers associated with points of
presence throughout the United States. Subscribers typically need bear no
expenses for communication beyond the cost, if any, of an ordinary local or
regional phone call. We estimate that our current set of local access numbers
covers the vast majority of the U.S. population. Our reliance on several
independent providers of network capacity has allowed us to provide high quality
service throughout the United States while negotiating progressively lower
telecommunications rates from these competing providers.
 
    The time each user spends connected to our central computers is minimized
through the use of a patented architecture that allows subscribers to read and
compose e-mail messages offline, connecting automatically to Juno's central
computer facilities only for the relatively brief period necessary to download
incoming mail or upload one or more outgoing messages. Advertisements are
downloaded to a subscriber's computer along with the subscriber's incoming
e-mail messages, and are displayed not only while the subscriber is actually
connected to our central facilities, but throughout the significantly longer
period during which he or she is reading and writing e-mail messages offline,
using only his or her own computer. The relatively large ratio between average
ad display time, an important revenue-related resource, and average connect
time, an important expense item, is essential to the economics of our basic
e-mail and Juno Gold services. Moreover, because we believe that almost a
quarter of all time spent online by subscribers to the leading Internet access
service is attributable to their reading and writing e-mail messages while
connected to the service's central computers, we believe that our offline e-mail
architecture could also confer an economic advantage on Juno Web.
 
                                       53
<PAGE>
SUBSCRIBER ACQUISITION
 
    The first phase of Juno's business strategy focused on maximizing total
subscriber count through the acquisition of large numbers of subscribers to our
free basic e-mail service. A number of acquisition channels have been employed
to achieve these goals, including:
 
    - ONLINE DISTRIBUTION. The Juno software may be downloaded free of charge
      from our promotional Web site (http://www.juno.com). In addition, we have
      formed relationships with a number of distribution partners who provide
      direct links to our Web site from their own Web sites at no cost to us.
 
    - DIRECT MAIL. Since early 1996, we have conducted several direct mail
      campaigns employing numerous creative approaches and mailing lists.
 
    - PASS-ALONG DISTRIBUTION. We encourage our basic e-mail subscribers to pass
      along the Juno software to their friends and associates or to suggest that
      they call our toll-free number to order a diskette or CD-ROM containing
      our software. This practice has historically accounted for a significant
      fraction of our new subscribers.
 
    - ORIGINAL EQUIPMENT MANUFACTURER BUNDLING. At various times since the
      launch of our basic e-mail service, the software necessary to use this
      service has been pre-loaded into a number of personal computers
      manufactured by IBM, Compaq, and Gateway, among others, and has been
      bundled along with models of desktop modems manufactured by U.S. Robotics.
      In February 1999, we signed an agreement with Hewlett-Packard to bundle
      our software with the installation software for several of their lines of
      printers.
 
    We have recently entered the second phase of our subscriber acquisition
program, which emphasizes the development of our billable subscriber base. Since
we launched Juno Gold and Juno Web on July 22, 1998, we have focused almost
exclusively on the upward migration of our free basic e-mail subscribers to
these billable subscription services. Subscribers to Juno's basic e-mail service
are exposed to a stream of marketing messages delivered through the Juno ad
system that encourage them to upgrade to Juno Gold or Juno Web. Juno Gold
members, in turn, are encouraged to upgrade to Juno Web.
 
                                     [LOGO]
 
                                       54
<PAGE>
    We cannot predict the ultimate rate of conversion to our billable
subscription services. We believe, however, that continuing increases in the
fraction of the general population using the Web, and in the number of e-mail
messages containing file attachments, may generate interest in the features
provided by our billable subscription services among new segments of our user
base over time. When users of Juno's basic e-mail service develop an interest in
using these types of higher-level services, we believe we are likely to benefit
from individuals' reluctance to switch e-mail addresses or split their Internet-
related activities between two service providers, which may make them more
likely to obtain advanced services from us than from another Internet access
provider. In addition, when a subscriber to our basic e-mail service is ready to
begin using a higher level of service, we believe that it will be easier and
more natural to do so by clicking on a button displayed on the Juno screen that
he or she is already using than by identifying and switching to an alternate
access provider. For risks associated with these beliefs, please see "Risk
Factors--Our business may suffer if we have difficulty acquiring subscribers to
our free basic e-mail service, Juno Gold or Juno Web."
 
    We also plan to launch a substantial marketing campaign designed to acquire
new subscribers directly into our billable subscription services utilizing
proceeds of this offering. See "--Our Strategy."
 
ADVERTISING AND STRATEGIC ALLIANCES
 
    ADVERTISING SALES
 
    Advertising plays an important role in the business models for each of our
three levels of service. We expect to derive significant revenues from the sale
of advertising displayed to any of the millions of individuals who send and
receive e-mail through the Juno system, regardless of the level of service to
which they subscribe. In addition, we expect to derive revenues from the display
of conventional Web advertising--sold, at least initially, by Lycos under a
revenue-sharing arrangement--on the co-branded Web pages that we make available
to our Juno Web subscribers.
 
    As of March 31, 1999, approximately 200 companies and organizations had
advertised on Juno, including a number of the world's largest advertisers. To
manage ad creation and campaign development, we maintain an in-house ad
production and client service staff. We also employ an internal sales force to
market our ad inventory, with the exception of the banner inventory on our
portal site, which is marketed by Lycos. See "--Our Services--Juno Web."
 
    TYPES OF ADVERTISING ON JUNO'S SERVICES
 
    In addition to Web banner ads displayed to Juno Web subscribers, we display
three distinct types of advertising:
 
    - BANNER ADS, which are displayed in the upper right-hand corner of the main
      Juno screen while the subscriber is reading or composing e-mail messages.
      Banner ads are displayed on a timed rotation, with a new ad typically
      appearing every 15, 20, or 30 seconds, and are interactive, offering
      viewers the opportunity to click on them and respond in any of a number of
      ways.
 
    - INTERSTITIAL ADS, which are displayed while a subscriber's modem is
      dialing into our central computers to send or receive e-mail, and are
      displayed for the duration of this telephone connection. Interstitial ads
      are approximately four times the size of a banner ad, and are displayed
      prominently at a time when the subscriber is not occupied with reading or
      writing mail.
 
    - POP-UP ADS that interrupt a user's session, and with which the subscriber
      must interact at least briefly before continuing with his or her session.
      Pop-up ads are most commonly displayed at the start of a session,
      immediately after the subscriber types in his or her password, and may
      contain any of the features of banner ads.
 
                                       55
<PAGE>
    Advertising may be purchased on a price-per-impression,
price-per-clickthrough, or price-per-response basis, or according to special
arrangements negotiated on a case-by-case basis. Each type of ad may be targeted
to a narrowly specified subset of our subscriber base based on data provided by
each subscriber in his or her Member Profile. While our privacy policies
preclude the dissemination to advertisers or other third parties of any of the
data contained in an individual's Member Profile without that individual's
permission, aggregate statistical information about the Juno subscriber base is
routinely provided to advertisers, and can be used to target specific ads to all
subscribers satisfying any specified combination of attributes.
 
    STRATEGIC MARKETING ALLIANCES
 
    We have formed a number of large-scale, strategic marketing alliances that
provide for substantial guaranteed payments to Juno as advances against various
forms of revenue-sharing:
 
    - AT&T WIRELESS SERVICES. Under this one-year agreement, AT&T will cover our
      ad transmission costs and other marketing expenses, and will provide us
      with a royalty payment for each new wireless subscriber recruited through
      Juno as well as a percentage of the revenue stream generated by those
      subscribers who do not already purchase other wireless services from AT&T.
 
   
    - FIRST USA. We recently entered into a multi-year marketing agreement with
      First USA which became effective on May 2, 1999. Under the terms of this
      agreement, we will receive payments each year--only the first year of
      which, however, is guaranteed--as a non-refundable advance against
      bounties paid for each new credit card, banking, or personal loan customer
      acquired through Juno. This relationship with First USA replaces a prior
      relationship with Bank of America that focused exclusively on the
      marketing of credit cards, and which was terminated by Bank of America
      effective May 1, 1999.
    
 
    - QWEST COMMUNICATIONS. Our multi-year agreement with Qwest Communications
      calls for guaranteed payments to Juno as a non-refundable advance against
      a substantial percentage of all revenues derived, on an ongoing basis,
      from telephone customers recruited through the Juno service.
 
    - THE HARTFORD. Our multi-year agreement with The Hartford provides for
      reimbursement of our marketing expenses as well as substantial guaranteed
      payments as an advance against both bounties paid when a Juno member
      purchases an insurance policy and an ongoing percentage of premiums
      collected from that subscriber.
 
    The multi-year agreements described above can typically be terminated on
short notice by either party, provided, however, that in some cases, the party
terminating the agreement is required to make specified payments to the other
party.
 
    SELECTED ADVERTISING CUSTOMERS AND STRATEGIC MARKETING PARTNERS
 
    As of March 31, 1999, approximately 200 advertisers and strategic marketing
partners had advertised on Juno, including those listed below.
 
Allstate
 
American Airlines
 
American Express
 
Ameritrade
 
AT&T Wireless Services
 
Audio Book Club
 
Bank of America
 
BSG Laboratories
 
Cendant
 
Citibank
 
Columbia House
 
CompuCom Systems
 
Computer Associates
 
Computer Discount Warehouse
 
Comtrad Industries
 
DaimlerChrysler
 
DeLorme
 
DIRECTV
 
Dragon Systems
 
Edmark
 
Fidelity Investments
 
                                       56
<PAGE>
First Union
 
First USA
 
Grolier
 
Hoechst Marion Roussel
 
IBM
 
Intel
 
Intuit
 
Invesco Funds Group
 
Isuzu
 
John Hancock
 
Lexmark
 
Market Facts
 
Microsoft
 
Microtek
 
National Consumer Bankruptcy Coalition
 
National Education Association
 
Network Associates
 
Network Solutions
 
Northwest Airlines
 
Office of National
  Drug Control Policy
 
Okidata
 
Philips Electronics
 
PKWARE
 
Platinum Capital Group
 
PowerQuest
 
Procter & Gamble
 
Protection One
 
Qwest Communications
 
Ralston Purina
 
Reed Elsevier
 
Sheraton Hotels and Resorts
 
Sierra On-Line
 
Stock Smart
 
Symantec
 
SyQuest
 
The Hartford
 
The Learning Company
 
The Signature Group
 
The Zone Network
 
U.S. Army
 
U.S. News & World Report
 
ViewSonic
 
Zoom Telephonics
 
    In a relatively small number of instances, we have provided advertising
credit to other companies in return for distribution of the Juno software, or
have exchanged advertising space with companies on a barter basis.
 
DIRECT PRODUCT SALES
 
    In addition to selling ads to third parties, we use part of our available
advertising inventory to conduct a variety of direct response marketing
campaigns on our own behalf. Direct Alliance currently supplies the bulk of the
merchandise we sell to our subscribers. We also rely on Direct Alliance for the
warehousing, fulfillment, billing, and customer service aspects of most of our
direct product sales activities. Since initiating our direct product sales
program in late 1996, we have sold computer hardware and software, books,
consumer electronics, entertainment products, and other merchandise to our
subscribers. While the margins associated with these products are typically
lower than those associated with the sale of paid advertising, our direct
product sales activities have provided what we believe to be a valuable
demonstration to paid advertisers of Juno's effectiveness as a transaction
medium. In addition, our willingness to feature an advertiser's products in our
own direct product sales campaigns has on several occasions contributed to the
successful closing of an advertising sale. We also sometimes use our direct
product sales infrastructure to assist paid advertisers in fulfilling product
requests generated through Juno.
 
    Since the beginning of 1998, our independent direct marketing activities
have been progressively displaced by an increasing stream of paid advertising,
strategic marketing alliances, and most recently, messages promoting Juno's own
billable subscription services. We expect that this trend will continue in the
future and, consequently, that the percentage of our revenues derived from
direct product sales will decrease over time. Even within the category of direct
marketing activities, the gradual replacement of direct product sales with
strategic marketing alliances should allow us to focus on the cost-effective
delivery of targeted direct sales messages, leaving other aspects of the direct
marketing process to specialized organizations that enjoy greater expertise,
economies of scale and other competitive advantages.
 
                                       57
<PAGE>
COMPETITION
 
    The market for Internet services is extremely competitive and includes a
number of substantial participants, including America Online, Microsoft and
AT&T. The markets for Internet-based advertising and direct product sales are
also very competitive. We believe that the primary competitive factors
determining success in these markets include a reputation for reliability and
service, effective customer support, pricing, easy-to-use software and
geographic coverage. Other important factors include the timing and introduction
of new products and services and industry and general economic trends. Our
ability to compete depends upon numerous factors, many of which are outside of
our control. We expect this competition to continue to increase because the
markets in which we operate face few substantial barriers to entry. Competition
may also intensify as a result of industry consolidation and the ability of some
of our competitors to bundle Internet services with other products and services.
Our current and potential competitors include many large national companies that
have substantially greater market presence and financial, technical,
distribution, marketing and other resources than we have. This may allow them to
devote greater resources than we can to the development, promotion and
distribution and sale of products and services.
 
    In recruiting subscribers for our billable subscription services, we
currently compete, or expect to compete, with the following types of companies,
among others:
 
    - Established online service providers such as America Online, CompuServe,
      and The Microsoft Network;
 
    - Independent national Internet service providers such as EarthLink,
      MindSpring, and Prodigy;
 
    - Numerous independent regional and local Internet service providers which
      may offer lower prices than a national Internet service provider;
 
    - Various national and local telephone companies such as AT&T, MCI WorldCom
      and Pacific Bell; and
 
    - Companies providing Internet access through "set-top boxes" connected to a
      user's television, such as WebTV, or through a "cable modem" connected to
      a user's personal computer, such as @Home.
 
    In addition, Microsoft and Netscape, publishers of the Web browsers utilized
by most Internet users, including subscribers to Juno Web, each own or are owned
by online or Internet service providers that compete with Juno Web.
 
    In providing e-mail-related services, we compete with Web-based e-mail
services such as Microsoft's Hotmail and USA.net's Net@ddress.
 
    With respect to the generation of advertising revenue, we compete with many
of the market participants listed above as well as with various
advertising-supported Web sites, including "portal" sites such as Yahoo! and
Excite, "content" sites such as CNET and CNN.com, and interactive advertising
networks and agencies such as DoubleClick and 24/7 Media. We also compete with
traditional media such as print and television for a share of advertisers' total
advertising budgets. If advertisers perceive the Internet to be a limited or
ineffective advertising medium or perceive us to be less effective or less
desirable than other Internet advertising vehicles, advertisers may be reluctant
to advertise on our services. In selling products directly to our subscribers,
we compete with other Internet-based sellers as well as with stores and other
companies that do not distribute their products through the Internet. Many of
these competitors are larger than we are, enjoy greater economies of scale than
are available to us, have substantially greater resources than we have, and may
be able to offer more products or more attractive prices than we can.
 
                                       58
<PAGE>
    Our competition is likely to increase. We believe this will probably happen
as Internet service providers and online service providers consolidate and
become larger, more competitive companies, and as large diversified
telecommunications and media companies acquire Internet service providers. The
larger Internet service providers and online service providers, including
America Online, offer their subscribers services such as instant messaging,
community message boards, and personal Web-page hosting that we do not currently
provide. Some diversified telecommunications and media companies, such as AT&T,
have begun to bundle other services and products with Internet access services,
potentially placing us at a significant competitive disadvantage. These
competitors may be able to charge less than we do for Internet services, causing
us to reduce, or preventing us from raising, fees for our billable subscription
services. The ability of our competitors to enter into strategic alliances or
joint ventures could also put us at a serious competitive disadvantage.
Competition could require us to increase our spending for sales and marketing as
well as for subscriber acquisition in order to maintain our position in the
marketplace, and could also result in increased subscriber attrition.
 
    For additional information, see "Risk Factors--Competition in the markets
for Internet services, Internet advertising and direct product sales is likely
to increase in the future and may harm our business."
 
GOVERNMENT REGULATION
 
    Providers of Internet access and e-mail services are not subject to direct
regulation by the Federal Communications Commission, but changes in the
regulatory environment relating to the telecommunications and media industries
could have an effect on our business. For example, several telecommunications
carriers are seeking to have communications over the Internet regulated by the
FCC in the same manner as other more traditional telecommunications services.
Local telephone carriers have also petitioned the FCC to regulate Internet
access providers in a manner similar to long distance telephone carriers and to
impose access fees on these providers, and recent events suggest that they may
be successful in obtaining the treatment they seek. In addition, we operate our
services throughout the United States, and regulatory authorities at the state
level may seek to regulate aspects of our activities as telecommunications
services. As a result, we could become subject to FCC and state regulation as
Internet services and telecommunications services converge.
 
    We remain subject to numerous additional laws and regulations that could
affect our business. Because of the Internet's popularity and increasing use,
new laws and regulations with respect to the Internet are becoming more
prevalent. These laws and regulations have covered, or may cover in the future,
issues such as:
 
    - user privacy;
 
    - pricing;
 
    - intellectual property;
 
    - federal, state and local taxation;
 
    - distribution; and
 
    - characteristics and quality of products and services.
 
    Legislation in these areas could slow the growth in use of the Internet
generally and decrease the acceptance of the Internet as a communications and
commercial medium. Additionally, because we rely on the collection and use of
personal data from our members for targeting advertisements shown on our
services, we may be harmed by any laws or regulations that restrict our ability
to collect or use this data. The Federal Trade Commission has begun
investigations into the privacy practices of companies
 
                                       59
<PAGE>
that collect information about individuals on the Internet. Although we are not
currently subject to direct regulation by the FTC, there can be no assurance
that we will not become subject to direct regulation in the future. It may take
years to determine how existing laws such as those governing intellectual
property, privacy, libel and taxation apply to the Internet. Any new legislation
or regulation regarding the Internet, or the application of existing laws and
regulations to the Internet, could harm us. Additionally, while we do not
currently operate outside of the United States, the international regulatory
environment relating to the Internet market could have an adverse effect on our
business, especially if we should expand internationally.
 
    The growth of the Internet, coupled with publicity regarding Internet fraud,
may also lead to the enactment of more stringent consumer protection laws. For
example, numerous bills have been presented to Congress and various state
legislatures designed to address the prevalence of unsolicited commercial bulk
e-mail on the Internet. These laws may impose additional burdens on our
business. The enactment of any additional laws or regulations in this area may
impede the growth of the Internet, which could decrease our potential revenues
or otherwise cause our business to suffer. For additional information, see "Risk
Factors--Changes in government regulation could decrease our revenues and
increase our costs."
 
INTELLECTUAL PROPERTY
 
    We have been granted three U.S. patents for technology related to the
offline display of advertisements and the authentication and dynamic scheduling
of advertisements and other messages to computer users. We have filed a number
of other patent applications relating to additional techniques for the operation
of online services and the provision of advertising messages. We cannot assure
you, however, that any of these applications will result in the issuance of
patents; that any patents that have been issued or that might be issued in the
future will provide us with any competitive advantages or will be exploited
profitably by us; or that any any of these patents will withstand any challenges
by third parties. Furthermore, we cannot assure you that we will be able to
obtain license rights to patents held by third parties that may be essential to
the successful implementation or operation of our services, or that patents held
or obtained by third parties will not otherwise harm our business or financial
results.
 
    Except as described above, we rely solely upon copyright and trademark law,
trade secret protection, and/or confidentiality agreements with our employees
and with some third parties to protect proprietary technology, processes, and
other intellectual property to the extent that protection is sought or secured
at all. We cannot assure you that any steps we might take will be adequate to
protect against misappropriation of our intellectual property by third parties.
Similarly, we cannot assure you that third parties will not be able to
independently develop similar technology, processes, or other intellectual
property. Furthermore, we cannot assure you that third parties will not assert
claims against us for infringement of their intellectual property rights.
 
   
    Rights to all intellectual property that was developed for our business at
our expense by personnel assigned to Juno by DESCO, L.P. were originally held by
DESCO, L.P. Through a series of assignments, DESCO, L.P. subsequently
transferred to us its right, title and interest in this intellectual property.
In connection with these assignments, we agreed to indemnify DESCO, L.P. against
any claims relating to the assignment of, or the use of, this intellectual
property. We do not have any right, title, or interest in any other intellectual
property created, developed, produced, or used by DESCO, L.P.
    
 
                                       60
<PAGE>
EMPLOYEES
 
    As of March 31, 1999, we employed 147 people, of whom 67 were in operations,
sales and marketing, and customer support; 53 were in engineering, product
development and network operations; and 27 were in finance, legal and
administration. Our employees are not covered by any collective-bargaining
arrangements, and we consider our relations with our employees to be good.
 
    As of March 31, 1999, we also retained the services of 47 people based in
Hyderabad, India who are employed by an India-based affiliate of DESCO, L.P. on
our behalf. These individuals are engaged in selected aspects of our software
development, customer service, ad production, and other activities that we
believe can be provided more economically overseas, and are provided to us under
an agreement with DESCO, L.P. Some of our back-office support functions are
provided to us by employees of DESCO, L.P. Please see "Certain Transactions" for
more information regarding our offices in New York.
 
FACILITIES
 
    Our principal executive office is located in New York, New York, where we
lease approximately 26,400 square feet. In addition, we lease additional office
space in New York City and also lease offices in Cambridge, Massachusetts and in
Washington, D.C. We believe that our existing facilities are adequate for our
current requirements and that additional space can be obtained on commercially
reasonable terms to meet our future requirements. Please see "Certain
Transactions" for more information regarding our offices in New York and
Cambridge.
 
LEGAL PROCEEDINGS
 
    We are not a party to any material legal proceedings.
 
                                       61
<PAGE>
                                   MANAGEMENT
 
DIRECTORS, EXECUTIVE OFFICERS AND KEY EMPLOYEES
 
   
    The directors, executive officers and key employees of Juno, and their ages
and positions as of May 5, 1999, are as follows:
    
 
   
<TABLE>
<CAPTION>
NAME                                         AGE                                   POSITION
- ---------------------------------------      ---      ------------------------------------------------------------------
<S>                                      <C>          <C>
Charles E. Ardai*......................          29   President and Director
Robert H. Cherins*.....................          59   Executive Vice President, Sales and Marketing
Mark A. Moraes*........................          33   Executive Vice President, Technology
Richard M. Eaton, Jr.*.................          38   Chief Financial Officer and Treasurer
Jordan S. Birnbaum.....................          28   Senior Vice President, Business Development
Richard D. Buchband....................          36   Senior Vice President and General Counsel
V. S. Mani.............................          35   Senior Vice President, Database Systems
Peter D. Skopp.........................          28   Senior Vice President, Network Development
David E. Shaw..........................          48   Chairman of the Board of Directors
Edward J. Ryeom........................          29   Director
Louis K. Salkind.......................          41   Director
</TABLE>
    
 
- ------------------------
 
*   Denotes Executive Officer.
 
    CHARLES E. ARDAI  has served as President of Juno since its inception in
June 1995. Mr. Ardai has served as a director of Juno since October 1997. From
January 1992 until June 1995, Mr. Ardai served DESCO, L.P. in a number of
positions--first as Director of Strategic Growth from January 1992 until January
1993, where he was responsible for the development and execution of DESCO,
L.P.'s recruitment strategies, then as Vice President from January 1993 until
January 1995. From January 1995 until June 1995, Mr. Ardai served as Senior Vice
President at DESCO, L.P., with responsibility for development of
Internet-related business ventures. Mr. Ardai also served as a Managing Director
of DESCO, L.P. from January 1998 until February 1999. Prior to joining DESCO,
L.P. in January 1992, Mr. Ardai worked at Davis Publications, where he was
responsible for the development and marketing of products derived from the
firm's media properties. During this period, he also maintained an independent
career as a freelance writer and editor. Mr. Ardai serves on the Advisory Board
of the Association for Interactive Media, and on the Markle Foundation's E-mail
For All Advisory Board. Mr. Ardai graduated SUMMA CUM LAUDE from Columbia
University.
 
    ROBERT H. CHERINS  has served as Juno's Executive Vice President, Sales and
Marketing since December 1996. From March 1993 until December 1996, Mr. Cherins
served as President of Jordan, McGrath, Case & Taylor/Direct and Executive Vice
President of its corporate parent, Jordan, McGrath, Case & Taylor. Previously,
Mr. Cherins spent 12 years with McCaffrey and McCall Advertising. He served as
Chairman and CEO of McCaffrey and McCall from 1987 to 1992 and as President from
1986 to 1987. Mr. Cherins served as President of McCaffrey and McCall's Direct
Marketing Division from 1981 to 1986. Mr. Cherins graduated from Hunter College
of the City University of New York.
 
    MARK A.  MORAES  has served as Juno's Executive Vice President, Technology
since February 1998. From February 1997 until February 1998, he served as a
Senior Vice President of Juno, with responsibility for the development and
operation of Juno's system and networks. From June 1995 until February 1997, Mr.
Moraes served in several positions in Juno's systems development group,
including Vice President. From April 1992 until June 1995, Mr. Moraes served as
a global systems architect at DESCO, L.P., where he designed data distribution
networks. Earlier, he made contributions to the development and roll-out of
UUNET Canada, to the X Windows environment, and to Usenet's news software, which
is used by tens of thousands of sites around the world. Mr. Moraes is also the
moderator of Usenet's news.announce.newusers newsgroup, which is read by tens of
thousands of new Usenet
 
                                       62
<PAGE>
users each year. Mr. Moraes received a Bachelor of Technology degree from the
Indian Institute of Technology and a Master of Applied Science degree from the
University of Toronto.
 
    RICHARD M. EATON, JR.  has served as Juno's Chief Financial Officer and
Treasurer since February 1999. From February 1998 until February 1999, Mr. Eaton
served as Juno's Senior Vice President, Finance and Administration. From
November 1996 until February 1998, he served as Juno's Vice President &
Corporate Controller. From May 1996 until November 1996, Mr. Eaton served as a
senior financial professional on a consulting basis for Think Systems
Corporation. From April 1995 to April 1996, Mr. Eaton served as Vice President &
Corporate Controller at Datalogix International, Inc. Mr. Eaton served as an
Area Controller of Finance and Administration for J. D. Edwards & Company from
August 1993 to December 1994. Mr. Eaton spent the first seven years of his
career with Coopers & Lybrand, last serving as an audit manager. Mr. Eaton
graduated SUMMA CUM LAUDE from the accelerated combined BBA/MBA degrees program
in public accountancy at Pace University, and is a member of both the
Connecticut Society of Certified Public Accountants and the American Institute
of Certified Public Accountants.
 
    JORDAN S. BIRNBAUM  has served as Juno's Senior Vice President, Business
Development since February 1998. He served as Juno's Vice President, Strategic
Marketing from February 1997 to February 1998 and as director of Juno's member
acquisition activities from October 1995 until February 1997. Prior to joining
Juno, Mr. Birnbaum held a number of positions with DESCO, L.P., most recently as
a London-based trader of equity securities from January 1994 until April 1995.
Mr. Birnbaum graduated from Cornell University.
 
    RICHARD D. BUCHBAND  has served as Juno's Senior Vice President and General
Counsel since February 1998, and is responsible for oversight of Juno's legal,
human resources and security policies. From January 1997 to February 1998, he
served as Vice President of Juno, and from September 1995 until January 1997 as
associate counsel of DESCO, L.P. Prior to September 1995, Mr. Buchband was a
corporate and transactional lawyer in New York. Mr. Buchband graduated MAGNA CUM
LAUDE with an A.B. from the Woodrow Wilson School of Public and International
Affairs at Princeton University and received his J.D. from Columbia Law School.
 
    V. S. MANI  has served as Juno's Senior Vice President, Database Systems
since February 1998. From February 1997 until February 1998, Mr. Mani served as
a Vice President, and from April 1996 until February 1997 as a software engineer
at Juno, with responsibility for the design of many of Juno's advertising and
electronic commerce systems. From February 1993 until March 1996, Mr. Mani held
a number of positions at the Matsushita Information Technology Laboratory in
Princeton, New Jersey, where he conducted research in information retrieval and
mobile computing, and, prior to that, with Digital Equipment Corporation. Mr.
Mani received his bachelor's degree with honors in Mechanical Engineering from
the Indian Institute of Technology and his M.S. in Computer Science from the
University of Wisconsin.
 
    PETER D. SKOPP  has served as Juno's Senior Vice President, Network
Development since February 1998. He served as a Vice President of Juno from
February 1997 to February 1998, with responsibility for designing Juno's server
software, and as a member of Juno's technical staff from December 1995 until
February 1997. From December 1992 until December 1995, Mr. Skopp was a manager
at the Programming Systems Laboratory of the Computer Science Department at
Columbia University. Mr. Skopp received his B.S. and M.S. degrees from Columbia
University.
 
    DAVID E. SHAW  served as Chairman of Juno Online Services, L.P. from its
inception in June 1995. He has served as a director of Juno since July 1996, and
was named Chairman of the Board of Juno in February 1999. Since November 1992,
Dr. Shaw has been the Chairman and President of D. E. Shaw & Co., Inc., the
parent of DESCO, L.P. Prior to founding a predecessor to DESCO, L.P. in 1988,
Dr. Shaw was a Vice President at Morgan Stanley & Co., where he managed the
firm's automated
 
                                       63
<PAGE>
trading technology group. Earlier, he served on the faculty of the Department of
Computer Science at Columbia University, and as President and founder of
Stanford Systems Corporation. In 1994, Dr. Shaw was appointed by President
Clinton to the President's Committee of Advisors on Science and Technology, in
which capacity he served as Chairman of the Panel on Educational Technology. Dr.
Shaw is also a member of the executive committee of the Council on
Competitiveness and of the board of directors of the American Association for
the Advancement of Science. He also serves as the (non-executive) Chairman of
the board of directors of Schrodinger, Inc., a developer of computational
chemistry software. Dr. Shaw graduated with highest honors from the University
of California at San Diego, and received his Ph.D. from Stanford University
following several years of research at the Stanford Artificial Intelligence
Laboratory.
 
   
    EDWARD J. RYEOM  has served as a director of Juno since March 1999. Since
January 1999, Mr. Ryeom has been a Partner of Prospect Street Ventures, a
venture capital firm focused on information technology investments. From May
1998 to December 1998, he was a Vice President of Prospect Street Ventures. From
August 1995 to May 1998, he was a Vice President in investment banking for
Brenner Securities. From May 1994 to June 1995, he worked at Cowen & Company, in
the information technology group. From May 1993 to May 1994, he was a consultant
with Andersen Consulting. Mr. Ryeom also serves as a director for several
private information technology companies. Mr. Ryeom graduated with a bachelor's
degree in Electrical Engineering from Columbia University, and an M.E. in
Systems Engineering from University of Virginia.
    
 
    LOUIS K. SALKIND  has served as a director of Juno since March 1999. Since
January 1991, Dr. Salkind has been a Managing Director of DESCO, L.P., where he
manages the firm's proprietary trading business. Since May 1993, he has also
been a Director of D. E. Shaw Securities International, a London-based affiliate
of DESCO, L.P., and since November 1997, he has been a Director of D. E. Shaw
Securities Hong Kong, Ltd. Dr. Salkind graduated CUM LAUDE with an A.B. from
Princeton University and received his M.S. and Ph.D degrees from New York
University.
 
COMPOSITION OF THE BOARD
 
   
    Upon the completion of this offering, we intend to file a revised
certificate of incorporation pursuant to which our board of directors will be
divided into three classes, each of whose members will serve for a staggered
three-year term. Upon the expiration of the term of a class of directors,
directors in that class will be elected for three-year terms at the annual
meeting of stockholders in the year in which their term expires. Our board of
directors has resolved that Mr. Ardai will be a Class I Director whose term
expires at the 2000 annual meeting of stockholders. Dr. Salkind will be a Class
II Director whose term expires at the 2001 annual meeting of stockholders. Mr.
Ryeom and Dr. Shaw will be Class III Directors whose terms expire at the 2002
annual meeting of stockholders. With respect to each class, a director's term
will be subject to the election and qualification of their successors, or their
earlier death, resignation or removal.
    
 
BOARD COMMITTEES
 
    The Audit Committee of the board of directors reviews, acts on and reports
to the board of directors with respect to various auditing and accounting
matters, including the recommendation of Juno's auditors, the scope of the
annual audits, fees to be paid to the auditors, the performance of Juno's
independent auditors and the accounting practices of Juno. The members of the
Audit Committee are Mr. Ryeom, and Drs. Salkind and Shaw.
 
    The Compensation Committee of the board of directors recommends, reviews and
oversees the salaries, benefits and stock option plans for Juno's employees,
consultants, directors and other individuals compensated by Juno. The
Compensation Committee will also administer Juno's compensation plans. The
members of the Compensation Committee are Messrs. Ardai and Ryeom, and Dr. Shaw.
 
                                       64
<PAGE>
DIRECTOR COMPENSATION
 
    Other than reimbursing directors for customary and reasonable expenses of
attending board of directors or committee meetings, Juno does not currently
compensate its directors. On April 9, 1999, Drs. Salkind and Shaw, and Mr.
Ryeom, as non-employee board members, were each granted an option to purchase
22,222 shares of common stock with an exercise price of $9.00 per share, which
will become exercisable upon the completion of four months of board service
measured from that date. Additionally, under our 1999 Stock Incentive Plan each
individual who first joins the Juno board after the effective date of this
offering as a non-employee board member will automatically receive a grant of an
option on that date to purchase 22,222 shares of common stock at the time of his
or her commencement of board service. In addition, on the date of each annual
stockholders' meeting beginning in 2000, each non-employee member of the board
of directors who is to continue to serve as a non-employee board member will
automatically be granted an option to purchase 7,777 shares of common stock.
Please see "--1999 Stock Incentive Plan".
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
    Juno did not have a Compensation Committee during 1998. During 1998, Mr.
Ardai and Dr. Shaw made decisions relating to compensation of Juno's executive
officers, except that Mr. Ardai did not participate in discussions regarding his
own compensation. No executive officer of Juno serves on the board of directors
or compensation committee of any entity which has one or more executive officers
serving as a member of Juno's board of directors or Compensation Committee.
 
EMPLOYMENT, SEVERANCE AND OTHER ARRANGEMENTS
 
   
    Juno has entered into an employment agreement with Charles E. Ardai, dated
April 26, 1999, which may be terminated by either party upon 30 days notice. The
agreement provides for Mr. Ardai to receive a base salary of $185,000 and to
receive semi-annual bonus payments on January 1 and July 1 of each year,
starting on July 1, 1999, of not less than $50,000 each. The agreement became
effective on May 1, 1999 for calendar year 1999. Subsequent to calendar year
1999, Mr. Ardai's base salary and bonus amount may be increased, decreased or
eliminated in the sole discretion of Juno.
    
 
   
    Juno has entered into an employment agreement with Robert H. Cherins, dated
April 26, 1999, which may be terminated by either party upon 30 days notice. The
agreement, which incorporates the terms of a letter agreement dated November 20,
1996, provides for Mr. Cherins to receive a base salary of $150,000. The
agreement also provides for Mr. Cherins to receive a non-refundable advance of
$178,500, to be paid semi-monthly and deducted against any year-end bonus. The
agreement became effective on May 1, 1999 for calendar year 1999. Although Mr.
Cherins is eligible under the agreement to receive a year-end bonus, Juno does
not expect to pay him an additional year-end bonus with respect to calendar year
1999. Subsequent to calendar year 1999, Mr. Cherins's base salary, bonus amount
and the amount of the non-refundable advance may be increased or decreased in
the sole discretion of Juno, provided that, for each calendar year he is
employed by Juno, his base salary and the amount of the non-refundable advance
shall not be less than $328,500. In addition, in the event that Mr. Cherins is
discharged by Juno prior to January 1, 2000, unless he is terminated for cause
or becomes unable to work due to disability, Juno shall be required to offer Mr.
Cherins a one-year engagement, at a rate of $328,500 per annum, to provide those
consulting services as Juno may determine in its sole discretion, provided,
however, that if Mr. Cherins has been engaged as a consultant for Juno for the
entire nine-month period immediately following the commencement of his
consultancy, then Juno shall be obligated to pay three months additional
severance to Mr. Cherins at a rate of $328,500 per annum. In the event that Mr.
Cherins is discharged by Juno on or after January 1, 2000, unless he is
terminated for cause or becomes unable to work due to disability, Juno shall pay
Mr. Cherins three months of severance at a rate of $328,500 per annum.
    
 
                                       65
<PAGE>
    DESCO, L.P., acting for the benefit of Juno, has entered into an employment
agreement with Mark A. Moraes, dated April 6, 1998, under which Mr. Moraes works
on a full-time basis for Juno. This agreement may be terminated by Juno or Mr.
Moraes upon 30 days notice. The agreement provides that Mr. Moraes will receive
a base salary of $150,000 for calendar year 1998 and will be eligible to receive
a bonus at the sole discretion of the President of Juno. Subsequent to calendar
year 1998, Mr. Moraes' base salary and bonus amount may be increased, decreased
or eliminated in the sole discretion of the President of Juno.
 
    Juno has entered into an employment agreement with Richard M. Eaton, Jr.,
dated September 25, 1998, which may be terminated by either party upon 30 days
notice. Pursuant to the agreement Mr. Eaton received a base salary of $125,000
in 1998 and was eligible to receive a bonus in the sole discretion of the
President of Juno. Mr. Eaton also received a non-refundable advance in the
amount of $30,000 in 1998, which was deducted against the bonus amount paid for
1998. Subsequent to calendar year 1998, Mr. Eaton's base salary, bonus amount
and the amount of the non-refundable advance may be increased or decreased in
the sole discretion of the President of Juno. Juno has agreed to pay Mr. Eaton
$13,333 in deferred compensation on December 31, 1999, provided that he has not
voluntarily terminated his employment prior to that date or been dismissed for
cause.
 
    Juno has also granted specified rights to some of our officers in the event
that they are terminated without cause or in the event that they voluntarily
resign following a material reduction in their duties and responsibilities or
their cash compensation or a relocation of their place of employment.
 
                                       66
<PAGE>
EXECUTIVE COMPENSATION
 
    The following table sets forth all compensation awarded to, earned by or
paid to Juno's chief executive officer and the other three executive officers of
Juno whose annual salary and bonus exceeded $100,000 in 1998 for services
rendered in all capacities during 1998.
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                                                   LONG-TERM
                                                                        ANNUAL COMPENSATION      COMPENSATION
                                                                                (1)                 AWARDS
                                                                       ----------------------  SHARES UNDERLYING
NAME AND PRINCIPAL POSITION                                              SALARY      BONUS          OPTIONS
- ---------------------------------------------------------------------  ----------  ----------  -----------------
<S>                                                                    <C>         <C>         <C>
Charles E. Ardai.....................................................  $  300,000  $       --         238,711
  President
Robert H. Cherins....................................................  $  150,000  $  300,000          17,600
  Executive Vice President,
  Sales and Marketing
Mark A. Moraes (2)...................................................  $  150,000  $  200,000         139,200
  Executive Vice President,
  Technology
Richard M. Eaton, Jr.................................................  $  125,000  $   90,000          64,569
  Chief Financial Officer and
  Treasurer
</TABLE>
 
- ------------------------
 
(1) The column for "Other Annual Compensation" has been omitted because there is
    no compensation required to be reported in that column. The aggregate amount
    of perquisites and other personal benefits provided to each executive
    officer above is less than the lesser of $50,000 and 10% of the total annual
    salary and bonus of that officer.
 
(2) Mr. Moraes is employed by DESCO, L.P. but works for Juno under the terms of
    his agreement with DESCO, L.P. Juno has agreed to pay Mr. Moraes a one-time
    bonus of $100,000 in connection with overseeing the delivery to Juno of
    consulting services provided by India-based affiliates of DESCO, L.P. See
    "Certain Transactions--Shared Services." The 1998 portion of this one-time
    bonus is $75,000 and is included in the amounts presented above. The
    remaining portion of this one-time bonus will be included in Mr. Moraes'
    1999 bonus.
 
                                       67
<PAGE>
OPTION GRANTS IN LAST YEAR
 
    The following table sets forth information regarding options granted to
Juno's executive officers during the year ended December 31, 1998. In the year
ended December 31, 1998, Juno Online Services, L.P. granted options to purchase
units, which converted into options to purchase 1,577,437 shares of common stock
following the statutory merger with Juno Online Services, Inc.  Juno has not
granted any stock appreciation rights.
 
<TABLE>
<CAPTION>
                                                    INDIVIDUAL GRANTS(1)                            POTENTIAL REALIZABLE
                                ------------------------------------------------------------          VALUE AT ASSUMED
                                 NUMBER OF                                                              ANNUAL RATES
                                SECURITIES                                                       OF STOCK PRICE APPRECIATION
                                UNDERLYING        % OF TOTAL         EXERCISE                        FOR OPTION TERM(2)
                                  OPTIONS     OPTIONS GRANTED TO       PRICE     EXPIRATION   ---------------------------------
NAME                              GRANTED      EMPLOYEES IN 1998     PER SHARE      DATE         0%          5%         10%
- ------------------------------  -----------  ---------------------  -----------  -----------  ---------  ----------  ----------
<S>                             <C>          <C>                    <C>          <C>          <C>        <C>         <C>
Charles E. Ardai..............     189,244              12.0%        $    0.45     02/16/08   $       0  $   53,557  $  135,724
                                    49,467               3.1              1.35     10/04/08      56,866     134,660     253,979
Robert H. Cherins.............       3,422               0.2              0.45     02/16/08           0         968       2,454
                                    14,178               0.9              1.35     10/04/08      16,304      38,595      72,793
Mark A. Moraes................      59,984               3.8              0.45     02/16/08           0      16,976      43,021
                                    79,216               5.0              1.35     10/04/08      91,097     215,643     406,720
Richard M. Eaton, Jr..........      25,852               1.6              0.45     02/16/08           0       7,316      18,541
                                    38,717               2.5              1.35     10/04/08      44,524     105,395     198,785
</TABLE>
 
- ------------------------
 
(1) Each option represents the right to purchase one share of common stock. The
    options shown in this column, which were originally granted pursuant to Juno
    Online Services, L.P.'s 1997 Class B Unit Option/Issuance Plan, vest at a
    rate of 20% per annum over five years, but did not become exercisable by
    option holders until the statutory merger of Juno Online Services, L.P. with
    and into Juno Online Services, Inc. in March 1999. See "--1999 Stock
    Incentive Plan."
 
(2) Amounts represent hypothetical gains that could be achieved for the
    respective options if exercised at the end of the option term. The 0%, 5%
    and 10% assumed annual rates of compounded stock price appreciation are
    mandated by rules of the Securities and Exchange Commission and do not
    represent Juno's estimate or projection of Juno's future common stock
    prices. These amounts represent assumed rates of appreciation in the value
    of Juno's common stock from the deemed fair market value for accounting
    purposes on the date of grant. Actual gains, if any, on stock option
    exercises are dependent on the future performance of the common stock and
    overall stock market conditions. The amounts reflected in the table may not
    necessarily be achieved.
 
                                       68
<PAGE>
AGGREGATED OPTION EXERCISES IN THE YEAR ENDED DECEMBER 31, 1998 AND YEAR-END
  OPTION VALUES
 
    The following table sets forth information concerning the number and value
of unexercised options held by each of Juno's executive officers at December 31,
1998. None of the executive officers exercised options during the year ended
December 31, 1998. Under the terms of the 1997 Class B Unit Option/Issuance
Plan, options remained unexercisable by the option holders until the statutory
merger of Juno Online Services, L.P. with and into Juno Online Services, Inc. in
March 1999. This table assumes the conversion of Juno Online Services, L.P. to a
corporate form of organization as of December 31, 1998.
 
<TABLE>
<CAPTION>
                                                               NUMBER OF SECURITIES
                                                              UNDERLYING UNEXERCISED       VALUE OF UNEXERCISED
                                                                    OPTIONS AT             IN-THE-MONEY OPTIONS
                                                                DECEMBER 31, 1998        AT DECEMBER 31, 1998(1)
                                                            --------------------------  --------------------------
<S>                                                         <C>          <C>            <C>          <C>
NAME                                                        EXERCISABLE  UNEXERCISABLE  EXERCISABLE  UNEXERCISABLE
- ----------------------------------------------------------  -----------  -------------  -----------  -------------
Charles E. Ardai..........................................      72,958        348,153    $ 204,282    $   930,308
Robert H. Cherins.........................................      72,958        127,042      204,282        342,957
Mark A. Moraes............................................      24,319        175,683       68,093        420,613
Richard M. Eaton, Jr......................................       9,728         79,162       27,238        186,805
</TABLE>
 
- ------------------------
 
(1) There was no public trading market for the common stock of Juno as of
    December 31, 1998. The deemed fair market value for accounting purposes on
    December 31, 1998 was determined to be $3.25 per share.
 
1999 STOCK INCENTIVE PLAN
 
    The 1999 Stock Incentive Plan is intended to serve as the successor equity
incentive program to Juno's 1997 Class B Limited Partnership Unit
Option/Issuance Plan. The 1999 Stock Incentive Plan became effective on March
26, 1999.
 
    Juno has authorized 5,768,611 shares of common stock for issuance under the
1999 Stock Incentive Plan. This share reserve consists of the shares which were
available for issuance under the 1997 Limited Partnership Plan on the effective
date of the 1999 Stock Incentive Plan plus an additional increase of 2,645,855
shares. The share reserve will automatically be increased on the first trading
day of January each calendar year, beginning in January 2000, by a number of
shares equal to 1% of the total number of shares of common stock outstanding on
the last trading day of the immediately preceding calendar year, but no such
annual increase will exceed 444,444 shares. However, in no event may any one
participant in the 1999 Stock Incentive Plan receive option grants or direct
stock issuances for more than 1,111,111 shares in the aggregate per calendar
year.
 
    Outstanding options under the 1997 Limited Partnership Plan will be
incorporated into the 1999 Stock Incentive Plan upon the date of this offering,
and no further option grants will be made under the 1997 Limited Partnership
Plan. The incorporated options will continue to be governed by their existing
terms, unless Juno's Compensation Committee extends one or more features of the
1999 Stock Incentive Plan to those options. However, except as otherwise noted
below, the outstanding options under the 1997 Limited Partnership Plan contain
substantially the same terms and conditions summarized below for the
discretionary option grant program under the 1999 Stock Incentive Plan.
 
    The 1999 Stock Incentive Plan has four separate programs. The first program
is the discretionary option grant program under which eligible individuals in
Juno's employ or service, including officers, non-employee board members and
consultants, may be granted options to purchase shares of Juno's common stock.
The second program is the stock issuance program under which eligible
individuals may be issued shares of common stock directly, through the purchase
of such shares or as a bonus tied to the performance of services. The third
program is the salary investment option grant program under
 
                                       69
<PAGE>
which executive officers and other highly compensated employees may elect to
apply a portion of their base salary to the acquisition of special below-market
stock option grants. The fourth program is the automatic option grant program
under which option grants will automatically be made at periodic intervals to
eligible non-employee board members.
 
    The discretionary option grant and stock issuance programs will be
administered by Juno's Compensation Committee. This committee will determine
which eligible individuals are to receive option grants or stock issuances, the
time or times when option grants or stock issuances are to be made, the number
of shares subject to each grant or issuance, the exercise or purchase price for
each grant or issuance, the status of any granted option as either an incentive
stock option or a non-statutory stock option under the federal tax laws, the
vesting schedule to be in effect for the option grant or stock issuance and the
maximum term for which any granted option is to remain outstanding. The
committee will also select the executive officers and other highly compensated
employees who may participate in the salary investment option grant program in
the event that program is activated for one or more calendar years. Neither the
Compensation Committee nor the board will exercise any administrative discretion
with respect to option grants made under the salary investment option grant
program or under the automatic option grant program for the non-employee board
members.
 
    The exercise price for the options may be paid in cash or in shares of
Juno's common stock valued at fair market value on the exercise date. The option
may also be exercised through a same-day sale program without any cash outlay by
the optionee. In addition, the Compensation Committee may allow a participant to
pay the option exercise price or direct issue price, and any associated
withholding taxes incurred in connection with the acquisition of shares, with a
full-recourse, interest-bearing promissory note.
 
    In the event that Juno is acquired, whether by merger or asset sale or sale
by the stockholders of more than 50% of Juno's voting stock in a transaction
recommended by the board of directors, each outstanding option under the
discretionary option grant program which is not to be assumed by the successor
corporation or otherwise continued will automatically accelerate in full, and
all unvested shares under the discretionary option grant and stock issuance
programs will immediately vest, except to the extent Juno's repurchase rights
with respect to those shares are to be assigned to the successor corporation or
otherwise continued in effect. The Compensation Committee may grant options
under the discretionary option grant program which will accelerate in the event
of an acquisition even if the options are assumed or which will accelerate if
the optionee's service is subsequently terminated. The Compensation Committee
may grant options and issue shares which accelerate in connection with a hostile
change in control effected through a successful tender offer for more than 50%
of Juno's outstanding voting stock or by proxy contest for the election of board
members, or which accelerate upon a subsequent termination of an individual's
service.
 
    Options currently outstanding under the 1997 Limited Partnership Plan may be
assumed by the successor corporation in an acquisition; such options are not by
their terms subject to acceleration at the time of an acquisition or a change in
control or upon the termination of the optionee's service following any such
transaction.
 
    Stock appreciation rights may be issued under the discretionary option grant
program which will provide the holders with the option to surrender their
outstanding options for an appreciation distribution from Juno equal to the fair
market value of the vested shares subject to the surrendered option less the
aggregate exercise price payable for such shares. Such appreciation distribution
may be made in cash or in shares of Juno's common stock. There are currently no
outstanding stock appreciation rights under the 1997 Limited Partnership Plan.
 
    The Compensation Committee has the authority to cancel outstanding options
under the discretionary option grant program, including options incorporated
from the 1997 Limited Partnership Plan,
 
                                       70
<PAGE>
in return for the grant of new options for the same or different number of
option shares with an exercise price per share based upon the fair market value
of the common stock on the new grant date.
 
    In the event the Compensation Committee elects to activate the salary
investment option grant program for one or more calendar years, each of Juno's
executive officers and other highly compensated employees selected for
participation may elect to reduce his or her base salary for that calendar year
by a specified dollar amount not less than $5,000 nor more than $50,000. In
return, the individual will automatically be granted, on the first trading day
in the calendar year for which the salary reduction is to be in effect, a
non-statutory option to purchase that number of shares of common stock
determined by dividing the salary reduction amount by two-thirds of the fair
market value per share of Juno's common stock on the grant date. The option
exercise price will be equal to one-third of the fair market value of the option
shares on the grant date. As a result, the fair market value of the option
shares on the grant date less the exercise price payable for those shares will
be equal to the salary reduction amount. The option will become exercisable in a
series of 12 equal monthly installments over the calendar year for which the
salary reduction is to be in effect and will be subject to full and immediate
vesting in the event of an acquisition or change in control of Juno.
 
    Under the automatic option grant program, each individual who first joins
the Juno board after the effective date of this offering as a non-employee board
member will automatically be granted an option for 22,222 shares of Juno common
stock at the time of his or her commencement of board service. In addition, on
the date of each annual stockholders meeting, beginning with the meeting in the
year 2000, each individual who is to continue to serve as a non-employee board
member will receive an option grant to purchase 7,777 shares of Juno common
stock. Each automatic grant will have an exercise price equal to the fair market
value per share of Juno common stock on the grant date and will have a maximum
term of 10 years, subject to earlier termination following the optionee's
cessation of board service. Each 22,222-share option will become exercisable
upon the optionee's completion of 4 months of board service measured from the
option grant date and each 7,777-share option grant will become exercisable upon
the optionee's completion of 6 months of service measured from the grant date.
However, each outstanding option will immediately vest upon an acquisition or
change in control or the death or disability of the optionee while serving as a
board member.
 
    Limited stock appreciation rights will automatically be included as part of
each grant made under the automatic option grant and salary investment option
grant programs and may be granted to one or more officers as part of their
option grants under the discretionary option grant program. Options with this
limited stock appreciation right may be surrendered to Juno upon the successful
completion of a hostile tender offer for more than 50% of Juno's outstanding
voting stock. In return for the surrendered option, the optionee will be
entitled to a cash distribution from Juno in an amount per surrendered option
share equal to the highest price per share of common stock paid in connection
with the tender offer less the exercise price payable for such share.
 
    The board may amend or modify the 1999 Stock Incentive Plan at any time,
subject to any required stockholder approval. The 1999 Stock Incentive Plan will
terminate no later than March 25, 2009.
 
1999 EMPLOYEE STOCK PURCHASE PLAN
 
    The board has approved the 1999 Employee Stock Purchase Plan, which is
expected to be approved by the stockholders prior to the date of this offering.
The plan will become effective immediately upon the execution of the
underwriting agreement for this offering. The plan is designed to allow eligible
employees of Juno and any participating subsidiaries to purchase shares of
common stock, at semi-annual intervals, through periodic payroll deductions. A
total of 555,556 shares of Juno's common stock will be issued under the plan.
 
                                       71
<PAGE>
    The plan will have a series of successive offering periods, each with a
maximum duration of 24 months. However, the initial offering period will begin
on the day the underwriting agreement is executed in connection with this
offering and will end on the last business day in July 2001. The next offering
period will begin on the first business day in August 2001, and subsequent
offering periods will be set by Juno's Compensation Committee.
 
    Individuals who are eligible employees on the start date of any offering
period may enter the plan on that start date or on any subsequent semi-annual
entry date, generally February 1 or August 1 each year. Individuals who become
eligible employees after the start date of the offering period may join the plan
on any subsequent semi-annual entry date within that period.
 
    A participant may contribute up to 15% of his or her cash earnings through
payroll deductions and the accumulated payroll deductions will be applied to the
purchase of shares on the participant's behalf on each semi-annual purchase
date, the last business day in January and July each year. The purchase price
per share will be 85% of the lower of the fair market value of Juno's common
stock on the participant's entry date into the offering period or the fair
market value on the semi-annual purchase date. The first purchase date will
occur on the last business day in January 2000. In no event, however, may any
participant purchase more than 1,667 shares, nor may all participants in the
aggregate purchase more than 138,889 shares on any one semi-annual purchase
date. Should the fair market value of Juno's common stock on any semi-annual
purchase date be less than the fair market value on the first day of the
offering period, then the current offering period will automatically end and a
new offering period will begin, based on the lower fair market value.
 
    The board may at any time amend or modify the plan. The plan will terminate
no later than the last business day in July 2009.
 
                                       72
<PAGE>
                              CERTAIN TRANSACTIONS
 
FINANCINGS PRIOR TO THE STATUTORY MERGER
 
    From the formation of Juno Online Services, L.P. on June 30, 1995, until the
statutory merger of Juno Online Services, L.P. with Juno Online Services, Inc.
on March 1, 1999, we were financed through contributions of capital, primarily
from persons or entities affiliated with D. E. Shaw & Co., Inc. In return for
their investments, these investors received Class A limited partnership units.
 
    On March 1, 1999, we converted from a limited partnership into a C
corporation. As part of this conversion, Class A limited partnership units were
converted into shares of Series A redeemable convertible preferred stock at a
one-to-one ratio, and options to acquire Class B limited partnership units under
our 1997 Class B Unit Option/Issuance Plan were converted into options to
acquire common stock of Juno Online Services, Inc. at a one-to-one ratio.
 
1999 PRIVATE EQUITY INVESTMENT
 
    Following the statutory merger, we raised gross proceeds of $65.0 million by
completing a private placement of 10,138,716 shares of a newly authorized class
of Series B redeemable convertible preferred stock to a group of investors.
Investors in the private round of financing included Intel Corporation, News
Corporation, Prospect Street Ventures and Sycamore Ventures. We undertook this
round of financing to raise capital necessary to fund our ongoing operations,
the planned expansion of our marketing activities and other general corporate
purposes.
 
    Upon completion of this offering, the outstanding shares of Series A
redeemable convertible preferred stock and Series B redeemable convertible
preferred stock will automatically convert to an aggregate of 27,822,751 shares
of our common stock.
 
SHARED SERVICES
 
    Historically, DESCO, L.P. has provided Juno various administrative services.
These services have included numerous overhead and infrastructure items, such as
providing office space and occupancy-related services, providing insurance and
professional services, providing and maintaining some of the hardware and
software used by Juno, and administering employee benefit plans for the benefit
of Juno employees. Prior to January 1, 1998, expenses related to these and other
services were charged to Juno on the basis of allocation metrics as determined
by DESCO, L.P, based upon square footage, headcount and other resources
utilized. Effective January 1, 1998, Juno and DESCO, L.P. entered into a
services agreement pursuant to which DESCO, L.P. has agreed to provide
administrative and other services for Juno in a specified set of service
categories, in return for a set monthly fee: $152,500 per month for the period
of January 1, 1998 to April 16, 1998 and $61,600 per month for the period
thereafter. The services agreement covers the delivery of:
 
    - telecommunications services;
 
    - personnel-related services, including for 401(k) and other benefit plans
      and workers compensation insurance;
 
    - occupancy services through April 18, 1998 for Juno personnel working in
      facilities maintained by DESCO, L.P.;
 
    - miscellaneous administrative services;
 
    - various professional services;
 
    - various purchasing services; and
 
    - various information technology services.
 
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<PAGE>
    The term of the services agreement extends on a month-to-month basis until
terminated by either party. The services agreement may be terminated by either
party at any time upon written notice to the other party following a material
default by the other party which remained uncured for 30 days or at any time
upon 90 days written notice to the other party. Juno believes that the amounts
charged to it under the services agreement are generally comparable to the
amounts that would have been charged by an independent third party. We do not
have any current plans to terminate the services agreement.
 
    Effective November 1, 1997, Juno and DESCO, L.P. entered into a services
agreement pursuant to which DESCO, L.P., through certain affiliates based in
India, has agreed to provide various consulting services to Juno. Under this
agreement, DESCO, L.P. provides technical and non-technical consulting services
as well as other consulting services agreed to by the parties. Under this
agreement, DESCO, L.P. is required, in consultation with Juno, to determine the
staffing it requires to perform the consulting services being provided to us.
Each staff member who performs consulting services under this agreement is
categorized as either a technical consultant or a non-technical consultant. In
addition to reimbursing DESCO, L.P. for specified expenses, such as travel costs
and satellite link charges, we are required to pay DESCO, L.P. $3,650 per month
for each technical consultant and $2,300 per month for each non-technical
consultant. The term of this agreement extends on a month-to-month basis until
terminated by either party. This agreement may be terminated by either party at
any time upon written notice to the other party following a material default by
the other party which remained uncured for 30 days or at any time upon 90 days
written notice to the other party. Juno is currently contemplating terminating
this agreement and changing the manner in which it obtains the services
currently provided under that agreement. Juno believes that the amounts charged
to it under this agreement are generally comparable to the amounts that would
have been charged by an independent third party.
 
    We employ a small number of personnel in Cambridge, Massachusetts, primarily
for the purpose of maintaining Juno server equipment that is located in a space
formerly maintained by D. E. Shaw Financial Technology, L.P., an affiliate of
DESCO, L.P. Prior to January 1, 1998, expenses connected with the use and
maintenance of that server equipment and the use of adjacent office space were
charged to Juno on the basis of allocation metrics as determined by DESCO, L.P.,
based upon square footage, headcount and other resources utilized. Effective
January 1, 1998, Juno and Shaw Financial Technology entered into a services
agreement under which Shaw Financial Technology has agreed to provide
information technology, telecommunications, occupancy, and related
administrative services to us, in return for a monthly fee of $11,500. Shaw
Financial Technology has recently sold some of its assets to a third party and
we have made arrangements with this third party to continue to host our server
equipment.
 
TRANSACTIONS WITH NEWS CORPORATION
 
    Juno has entered into an agreement with News America Incorporated, a
significant stockholder of Juno and an affiliate of News Corporation, to
purchase various forms of advertising on the media properties of News America
Incorporated and its affiliates. Under the March 1, 1999 agreement, Juno spent
$10.0 million for advertising that may be used at any time prior to March 2001,
to be provided by News America and its affiliates at then-current rates which
shall be no greater than those customarily applied to purchasers of similar
amounts of comparable advertising.
 
   
LEASES
    
 
   
    Prior to November 1997, most of Juno's staff occupied offices within space
leased by DESCO, L.P. in midtown Manhattan, with leasehold and other expenses
being allocated to Juno by DESCO, L.P. based on Juno's use of this space. In
November 1997, Juno relocated its New York-based staff and its principal
executive offices to a single floor at 1540 Broadway leased from Bertelsmann
Property, Inc. under an Agreement of Lease dated September 22, 1997 between
DESCO, L.P., as lessee, and Bertelsmann. The lease permits DESCO, L.P. to sublet
all or a portion of the premises to Juno. Juno
    
 
                                       74
<PAGE>
   
has agreed to assume the performance of DESCO, L.P.'s payment obligations under
the lease. The term of the lease continues until March 2003 and DESCO, L.P. has
an option to renew for an additional five-year term. The lease provides DESCO,
L.P. the right to terminate the lease effective January 1, 2000, if DESCO, L.P.
delivers a notice of termination to Bertelsmann on or prior to July 1, 1999. If
DESCO, L.P. terminates the lease under this provision, DESCO, L.P. must make
specified payments to Bertelsmann, including reimbursing it for rent that was
abated at the start of the lease. If DESCO, L.P. elects to terminate the lease
pursuant to the termination right described above, we would be required to
relocate our offices and enter into new lease arrangements. We cannot assure you
that the terms and conditions of any new lease would be as favorable to Juno as
this lease. In addition to the office space at 1540 Broadway, Juno currently
occupies two floors in an adjacent building under a subleasing arrangement with
DESCO, L.P. Although the terms of this arrangement have not been finalized, Juno
expects that the sublease will expire on April 30, 2001 and that Juno will have
the right to terminate on April 30, 2000 by providing three months prior notice
and making specified termination payments to DESCO, L.P. We believe that the
economic terms of this sublease will be generally comparable to those that could
be obtained from an independent third party.
    
 
INDEBTEDNESS TO RELATED PARTIES
 
    Juno has incurred indebtedness that, by its terms, is required to be repaid
upon the completion of this offering, or as otherwise described below.
 
    On March 31, 1998, Juno issued to D. E. Shaw Securities Group, L.P. a senior
note in the original principal amount of $10.0 million. The senior note bears
interest at the Federal Funds rate of interest plus 0.375%, and interest that is
not paid quarterly shall be satisfied by increasing the outstanding principal
amount of the senior note. Under the terms of the senior note, as amended, the
outstanding principal amount and any accrued but unpaid interest is to be paid
upon the earlier of December 31, 2000 or the date of completion of an initial
public offering by Juno which is registered under the Securities Act of 1933, as
amended. Juno is also required to make mandatory prepayments to Shaw Securities
in the event that Shaw Securities pays specified fees that are independently
owed to DESCO, L.P. On March 31, 1998, Shaw Securities and DESCO, L.P. entered
into a support agreement pursuant to which DESCO, L.P. agreed to pay Shaw
Securities in the event that Juno fails to make any of the mandatory
prepayments.
 
    As of March 31, 1999, the outstanding principal and interest under the
Senior Note was $8.8 million. Juno intends to repay all amounts owed under the
senior note with a portion of the proceeds of this offering.
 
OPTIONS GRANTED TO EXECUTIVE OFFICERS
 
    For information regarding the grant of stock options to executive officers
and directors, see "Management--Compensation of Directors," "--Executive
Compensation," "--1999 Stock Incentive Plan" and "Principal Stockholders."
 
                                       75
<PAGE>
                             PRINCIPAL STOCKHOLDERS
 
   
    The following table sets forth information with respect to the beneficial
ownership of the common stock as of May 5, 1999, and as adjusted to reflect the
sale of the shares of common stock offered hereby, by each person or group of
affiliated persons who is known by Juno to beneficially own 5% or more of the
common stock, each director and executive officer of Juno, and all directors and
executive officers of Juno as a group. Unless otherwise indicated, the address
of each beneficial owner listed below is c/o Juno Online Services, Inc., 1540
Broadway, New York, New York 10036.
    
 
   
    The following table gives effect to the shares of common stock issuable
within 60 days of May 5, 1999 upon the exercise of all options and other rights
beneficially owned by the indicated stockholders on that date. Beneficial
ownership is determined in accordance with the rules of the Securities and
Exchange Commission and includes voting and investment power with respect to
shares. Unless otherwise indicated, the persons named in the table have sole
voting and sole investment control with respect to all shares beneficially
owned.
    
 
<TABLE>
<CAPTION>
                                                                                            PERCENTAGE OF SHARES
                                                                  NUMBER OF SHARES           BENEFICIALLY OWNED
                                                                    BENEFICIALLY     ----------------------------------
BENEFICIAL OWNER                                                        OWNED         BEFORE OFFERING   AFTER OFFERING
- ----------------------------------------------------------------  -----------------  -----------------  ---------------
<S>                                                               <C>                <C>                <C>
David E. Shaw (1)...............................................       17,332,759             61.7%             50.1%
Shaw Family Trust IV (2)........................................        7,824,727             27.9              22.6
D. E. Shaw & Co., L.P. (3)......................................        6,336,734             22.6              18.3
News America Incorporated (4)...................................        3,135,198             11.1               9.1
Edward J. Ryeom (5).............................................          779,900              2.8               2.3
Louis K. Salkind (6)............................................          166,482                *                 *
Charles E. Ardai (7)............................................          147,286                *                 *
Robert H. Cherins (8)...........................................           73,642                *                 *
Mark A. Moraes (9)..............................................           48,476                *                 *
Richard M. Eaton, Jr. (10)......................................           14,898                *                 *
All directors and executive officers as a group
  (7 persons) (11)..............................................       18,563,443             65.6              53.3
</TABLE>
 
- ------------------------
 
*   Less than 1%.
 
   
(1) Includes (i) 2,830,337 shares held directly by David E. Shaw, (ii) 107,627
    shares held by D. E. Shaw & Co., Inc., (iii) 5,555,556 shares held by D. E.
    Shaw & Co., L.P., (iv) 781,178 shares held by
    D. E. Shaw Investment Group, L.P., and (v) 233,334 shares held by Shaw Juno
    Trust and (vi) 7,824,727 shares held by Shaw Family Trust IV. D. E. Shaw &
    Co., Inc., which is wholly owned by Dr. Shaw, is the general partner of D.
    E. Shaw & Co., L.P. D. E. Shaw & Co., L.P. is the general partner of D. E.
    Shaw Investment Group, L.P. Although Dr. Shaw is neither the trustee nor a
    beneficiary of the Shaw Juno Trust, some of the beneficiaries of the Shaw
    Juno Trust reside in Dr. Shaw's household. Dr. Shaw is the trustee of the
    Shaw Family Trust IV. Dr. Shaw disclaims beneficial ownership of the shares
    held by D. E. Shaw & Co., L.P., D. E. Shaw Investment Group, L.P., Shaw Juno
    Trust, and Shaw Family Trust IV, except to the extent of his pecuniary
    interest therein. The address of the foregoing entities is 120 West 45th
    Street, New York, New York 10036.
    
 
(2) Dr. Shaw is the trustee of the Shaw Family Trust IV. The address of Shaw
    Family Trust IV is 120 West 45th Street, New York, New York 10036.
 
(3) Includes (i) 5,555,556 shares held directly by D. E. Shaw & Co., L.P. and
    (ii) 781,178 shares held by D. E. Shaw Investment Group, L.P.  D. E. Shaw &
    Co., L.P. is the general partner of D. E. Shaw Investment Group, L.P. D. E.
    Shaw & Co., L.P. disclaims beneficial ownership of the shares held by D. E.
    Shaw Investment Group, L.P., except to the extent of its pecuniary interest
    therein. Dr. Shaw, as President of D. E. Shaw & Co., Inc., the General
    Partner of D. E. Shaw &
 
                                       76
<PAGE>
    Co., L.P., has voting and dispositive powers with respect to these shares.
    The address of D. E. Shaw & Co., L.P. is 120 West 45th Street, New York, New
    York 10036.
 
   
(4) News America Incorporated is an affiliate of News Corporation, a publicly
    traded company. The address of News America Incorporated is 1211 Avenue of
    the Americas, New York, New York 10036.
    
 
   
(5) Includes 701,910 shares held by Prospect Street NYC Discovery Fund, L.P. and
    77,990 shares held by Prospect Street NYC Co-Investment Fund, L.P. Mr. Ryeom
    is an officer of the general partner of each of these funds and he disclaims
    beneficial ownership of the shares held by these funds except to the extent
    of his pecuniary interest in each of them. The address of the foregoing
    entities is 10 East 40th Street, 44th Floor, New York, New York 10016.
    
 
   
(6) All of these shares are held by the Louis K. Salkind 1999 Grantor Retained
    Annuity Trust. Although Dr. Salkind is neither the trustee nor a beneficiary
    of the Louis K. Salkind 1999 Grantor Retained Annuity Trust, some of the
    beneficiaries of this trust reside in Dr. Salkind's household. The address
    of the Louis K. Salkind 1999 Grantor Retained Annuity Trust is 120 West 45th
    Street, New York, New York 10036.
    
 
   
(7) All of these shares are issuable upon the exercise of options. This number
    does not include 694,659 shares issuable upon the exercise of stock options
    that do not vest within 60 days of May 5, 1999.
    
 
   
(8) All of these shares are issuable upon the exercise of options. This number
    does not include 193,025 shares issuable upon the exercise of stock options
    that do not vest within 60 days of May 5, 1999.
    
 
   
(9) Includes 13,476 shares that are issuable upon the exercise of options. This
    number does not include 218,193 shares issuable upon the exercise of stock
    options that do not vest within 60 days of May 5, 1999.
    
 
   
(10) Includes 9,704 shares that are issuable upon the exercise of options. This
    number does not include 162,881 shares issuable upon the exercise of stock
    options that do not vest within 60 days of May 5, 1999.
    
 
(11) Includes 244,108 shares that are issuable upon the exercise of options.
 
                                       77
<PAGE>
                          DESCRIPTION OF CAPITAL STOCK
 
    The following description of Juno's common stock and preferred stock and
relevant provisions of Juno's amended and restated certificate of incorporation
as will be in effect upon the closing of this offering, and the amended and
restated bylaws as will be in effect upon the closing of this offering are
summaries thereof and are qualified by reference to our amended and restated
certificate of incorporation and the amended and restated bylaws, copies of
which have been filed with the Securities and Exchange Commission as exhibits to
Juno's Registration Statement, of which this prospectus forms a part. The
descriptions of the common stock and preferred stock reflect changes to Juno's
capital structure that will occur upon the closing of the offering in accordance
with the terms of our amended and restated certificate of incorporation.
 
    The authorized capital stock of Juno consists of 133,333,334 shares of
common stock, par value $.01 per share, and 5,000,000 shares of preferred stock,
par value $.01 per share.
 
COMMON STOCK
 
   
    As of May 5, 1999, there were 261,815 shares of common stock outstanding and
held of record by stockholders, without giving effect to the conversion of our
preferred stock. Based upon the number of shares outstanding as of that date and
giving effect to the issuance of the 6,500,000 shares of common stock in this
offering and the conversion of our outstanding shares of preferred stock upon
the completion of this offering, there will be 34,584,566 shares of common stock
outstanding upon the closing of this offering.
    
 
    Holders of common stock are entitled to one vote for each share held on all
matters submitted to a vote of stockholders and do not have cumulative voting
rights. Accordingly, holders of a majority of the shares of common stock
entitled to vote in any election of directors may elect all of the directors
standing for election. Holders of common stock are entitled to receive ratably
those dividends, if any, as may be declared by the board of directors out of
funds legally available therefor, subject to any preferential dividend rights of
any outstanding preferred stock. Upon the liquidation, dissolution or winding up
of Juno, the holders of common stock are entitled to receive ratably the net
assets of Juno available after the payment of all debts and other liabilities
and subject to the prior rights of any outstanding preferred stock. Holders of
the common stock have no preemptive, subscription, redemption or conversion
rights. The outstanding shares of common stock are, and the shares offered by
Juno in the offering will be, when issued in consideration for payment thereof,
fully paid and nonassessable. The rights, preferences and privileges of holders
of common stock are subject to, and may be adversely affected by, the rights of
the holders of shares of any series of preferred stock which Juno may designate
and issue in the future. Upon the closing of the offering, there will be no
shares of preferred stock outstanding.
 
PREFERRED STOCK
 
    Upon the closing of this offering, there will be no shares of redeemable
convertible preferred stock outstanding.
 
    Upon the closing of this offering, the board of directors will be
authorized, without further stockholder approval, to issue from time to time up
to an aggregate of 5,000,000 shares of preferred stock in one or more series and
to fix or alter the designations, preferences, rights and any qualifications,
limitations or restrictions of the shares of each series thereof, including the
dividend rights, dividend rates, conversion rights, voting rights, terms of
redemption, including sinking fund provisions, redemption price or prices,
liquidation preferences and the number of shares constituting any series or
designations of series. Juno has no present plans to issue any shares of
preferred stock. See "--Anti-Takeover Effects of Various Provisions of Delaware
Law and Juno's Certificate of Incorporation and Bylaws."
 
                                       78
<PAGE>
OPTIONS
 
   
    Options to purchase a total of 5,768,611 shares of common stock may be
granted under the 1999 Stock Incentive Plan. As of May 5, 1999, there were
outstanding options to purchase a total of 3,241,480 shares of common stock, of
which options to purchase approximately 430,507 shares will be exercisable upon
the closing of this offering. Since Juno intends to file a registration
statement on Form S-8 as soon as practicable following the closing of this
offering, any shares issued upon exercise of these options will be immediately
available for sale in the public market, subject to the terms of lock-up
agreements entered into by and between the holders of substantially all
outstanding options and the underwriters. See "Management--1999 Stock Incentive
Plan" and "Shares Eligible for Future Sale."
    
 
REGISTRATION RIGHTS
 
    Pursuant to the terms of the Amended and Restated Registration Rights
Agreement, after the closing of this offering the holders of 27,822,751 shares
of common stock will be entitled to demand registration rights with respect to
the registration of their shares under the Securities Act. The holders of 10% or
more of these shares are entitled to demand that Juno register their shares
under the Securities Act, subject to various limitations. Juno is not required
to effect more than six of these registrations pursuant to these demand
registration rights. In addition, pursuant to the Amended and Restated
Registration Rights Agreement, these holders will be entitled to piggyback
registration rights with respect to the registration of their shares under the
Securities Act, subject to various limitations. Further, at any time after Juno
becomes eligible to file a registration statement on Form S-3, the holders of
common stock who are parties to the Amended and Restated Registration Rights
Agreement may require Juno to file registration statements under the Securities
Act on Form S-3 with respect to their shares of common stock. These registration
rights are subject to certain conditions and limitations, among them the right
of the underwriters of an offering to limit the number of shares of common stock
held by security holders with registration rights to be included in a
registration. Juno is generally required to bear all of the expenses of all of
these registrations, except underwriting discounts and selling commissions.
Registration of any of the shares of common stock held by security holders with
registration rights would result in shares becoming freely tradable without
restriction under the Securities Act immediately upon effectiveness of such
registration.
 
ANTI-TAKEOVER EFFECTS OF VARIOUS PROVISIONS OF DELAWARE LAW AND JUNO'S
  CERTIFICATE OF INCORPORATION AND BYLAWS
 
    Juno is subject to the provisions of Section 203 of the Delaware General
Corporation Law. Subject to some exceptions, Section 203 prohibits a publicly
held Delaware corporation from engaging in a "business combination" with an
"interested stockholder" for a period of three years after the date of the
transaction in which the person became an interested stockholder, unless the
interested stockholder attained that status with the approval of the board of
directors or unless the business combination is approved in a prescribed manner.
A "business combination" includes mergers, asset sales and other transactions
resulting in a financial benefit to the interested stockholder. Subject to
various exceptions, an "interested stockholder" is a person who, together with
affiliates and associates, owns, or within three years did own, 15% or more of
the corporation's voting stock. This statute could prohibit or delay the
accomplishment of mergers or other takeover or change in control attempts with
respect to Juno and, accordingly, may discourage attempts to acquire Juno.
 
    In addition, various provisions of our amended and restated certificate of
incorporation and our amended and restated bylaws, which provisions will be in
effect upon the closing of the offering and are summarized in the following
paragraphs, may be deemed to have an anti-takeover effect and may delay, defer
or prevent a tender offer or takeover attempt that a stockholder might consider
in its best
 
                                       79
<PAGE>
interest, including those attempts that might result in a premium over the
market price for the shares held by stockholders.
 
    BOARD OF DIRECTORS VACANCIES.  Juno's amended and restated certificate of
incorporation authorizes the board of directors to fill vacant directorships or
increase the size of the board of directors. This may deter a stockholder from
removing incumbent directors and simultaneously gaining control of the board of
directors by filling the vacancies created by this removal with its own
nominees.
 
    STOCKHOLDER ACTION; SPECIAL MEETING OF STOCKHOLDERS.  Juno's amended and
restated certificate of incorporation provides that stockholders may not take
action by written consent, but only at duly called annual or special meetings of
stockholders. The amended and restated certificate of incorporation further
provides that special meetings of stockholders of Juno may be called only by the
chairman of the board of directors or a majority of the board of directors.
 
    ADVANCE NOTICE REQUIREMENTS FOR STOCKHOLDER PROPOSALS AND DIRECTOR
NOMINATIONS.  Juno's amended and restated bylaws provide that stockholders
seeking to bring business before an annual meeting of stockholders, or to
nominate candidates for election as directors at an annual meeting of
stockholders, must provide timely notice thereof in writing. To be timely, a
stockholder's notice must be delivered to or mailed and received at the
principal executive offices of Juno, not less than 120 days nor more than 150
days prior to the first anniversary of the date of Juno's notice of annual
meeting provided with respect to the previous year's annual meeting of
stockholders; provided, that if no annual meeting of stockholders was held in
the previous year or the date of the annual meeting of stockholders has been
changed to be more than 30 calendar days earlier than or 60 calendar days after
this anniversary, notice by the stockholder, to be timely, must be so received
not more than 90 days nor later than the later of:
 
    - 60 days prior to the annual meeting of stockholders or
 
    - the close of business on the 10th day following the date on which notice
      of the date of the meeting is given to stockholders or made public,
      whichever occurs first.
 
    Our amended and restated bylaws also specify certain requirements as to the
form and content of a stockholder's notice. These provisions may preclude
stockholders from bringing matters before an annual meeting of stockholders or
from making nominations for directors at an annual meeting of stockholders.
 
    AUTHORIZED BUT UNISSUED SHARES.  The authorized but unissued shares of
common stock and preferred stock are available for future issuance without
stockholder approval, subject to various limitations imposed by the Nasdaq
National Market. These additional shares may be utilized for a variety of
corporate purposes, including future public offerings to raise additional
capital, corporate acquisitions and employee benefit plans. The existence of
authorized but unissued and unreserved common stock and preferred stock could
make more difficult or discourage an attempt to obtain control of Juno by means
of a proxy contest, tender offer, merger or otherwise.
 
    The Delaware General Corporation Law provides generally that the affirmative
vote of a majority of the shares entitled to vote on any matter is required to
amend a corporation's certificate of incorporation or bylaws, unless a
corporation's certificate of incorporation or bylaws, as the case may be,
requires a greater percentage.
 
LIMITATION OF LIABILITY AND INDEMNIFICATION MATTERS
 
   
    Our amended and restated certificate of incorporation provides that the
liability of a director of Juno shall be eliminated or limited to the fullest
extent permitted by the Delaware General Corporation Law. Under the Delaware
General Corporation Law, the directors have a fiduciary duty to Juno which is
not eliminated by this provision of the amended and restated certificate of
incorporation and, in appropriate circumstances, equitable remedies such as
injunctive or other forms of non-monetary
    
 
                                       80
<PAGE>
relief will remain available. In addition, each director will continue to be
subject to liability under the Delaware General Corporation Law for:
 
    - breach of the director's duty of loyalty to Juno;
 
    - acts or omissions which are found by a court of competent jurisdiction to
      be not in good faith or which involve intentional misconduct, or knowing
      violations of law;
 
    - actions leading to improper personal benefit to the director; and
 
    - payment of dividends or approval of stock repurchases or redemptions that
      are prohibited by the Delaware General Corporation Law.
 
This provision also does not affect the directors' responsibilities under any
other laws, such as the Federal securities laws or state or Federal
environmental laws.
 
    Section 145 of the Delaware General Corporation Law empowers a corporation
to indemnify its directors and officers and to purchase insurance with respect
to liability arising out of their capacity or status as directors and officers,
provided that this provision shall not eliminate or limit the liability of a
director:
 
    - for any breach of the director's duty of loyalty to the corporation or its
      stockholders;
 
    - for acts or omissions not in good faith or which involve intentional
      misconduct or a knowing violation of law;
 
    - arising under Section 174 of the Delaware General Corporation Law; or
 
    - for any transaction from which the director derived an improper personal
      benefit.
 
    The Delaware General Corporation Law provides further that the
indemnification permitted thereunder shall not be deemed exclusive of any other
rights to which the directors and officers may be entitled under the
corporation's bylaws, any agreement, a vote of stockholders or otherwise. Our
amended and restated certificate of incorporation eliminates the personal
liability of directors to the fullest extent permitted by Section 102(b)(7) of
the Delaware General Corporation Law and provides that Juno shall fully
indemnify any person who was or is a party or is threatened to be made a party
to any threatened, pending or completed action, suit or proceeding, whether
civil, criminal, administrative or investigative, by reason of the fact that
that person is or was a director or officer of Juno, or is or was serving at the
request of Juno as a director or officer of another corporation, partnership,
joint venture, trust, employee benefit plan or other enterprise. This
indemnification shall be against expenses including attorney's fees, judgments,
fines and amounts paid in settlement actually and reasonably incurred by the
indemnitee in connection with such action, suit or proceeding.
 
    Juno has also entered into agreements to indemnify its directors and
executive officers, in addition to the indemnification provided for in Juno's
amended and restated bylaws. Juno believes that these provisions and agreements
are necessary to attract and retain qualified directors and executive officers.
Juno's amended and restated bylaws also permit it to secure insurance on behalf
of any officer, director, employee or other agent for any liability arising out
of his or her actions, regardless of whether the Delaware General Corporation
Law would permit indemnification. Juno intends to obtain liability insurance for
its officers and directors.
 
    At present, there is no pending litigation or proceeding involving any
director, officer, employee or agent as to which indemnification will be
required or permitted under the amended and restated certificate of
incorporation. Juno is not aware of any threatened litigation or proceeding that
may result in a claim for this type of indemnification.
 
TRANSFER AGENT AND REGISTRAR
 
    The transfer agent and registrar for the common stock is Continental Stock
Transfer & Trust Company, New York, New York.
 
                                       81
<PAGE>
                        SHARES ELIGIBLE FOR FUTURE SALE
 
    Prior to the offering, there has not been any public market for Juno's
common stock, and no prediction can be made as to the effect, if any, that
market sales of shares of common stock or the availability of shares of common
stock for sale will have on the market price of the common stock prevailing from
time to time. Nevertheless, sales of substantial amounts of common stock in the
public market could adversely affect the market price of the common stock and
could impair Juno's future ability to raise capital through the sale of its
equity securities.
 
   
    Upon the completion of this offering, Juno will have an aggregate of
34,584,566 shares of common stock outstanding, assuming no exercise of the
underwriters' over-allotment option and no exercise of outstanding options. Of
the outstanding shares, the 6,500,000 shares sold in the offering will be freely
tradable, except that any shares held by "affiliates" of Juno, as that term is
defined in Rule 144 promulgated under the Securities Act, may only be sold in
compliance with the limitations described below. The remaining 28,084,566 shares
of common stock will be deemed "restricted securities" as defined under Rule
144. Restricted securities may be sold in the public market only if registered
or if they qualify for an exemption from registration under Rules 144, 144(k) or
701 promulgated under the Securities Act, which rules are summarized below.
Subject to the lock-up agreements described below and the provisions of Rules
144, 144(k) and 701, additional shares will be available for sale in the public
market as follows:
    
 
   
<TABLE>
<CAPTION>
 NUMBER OF
   SHARES                                            DATE
- ------------  ----------------------------------------------------------------------------------
<C>           <S>
 
   6,500,000  After the date of this prospectus, freely tradable shares sold in this offering
              and shares saleable under Rule 144(k) that are not subject to the 180-day lock-up
 
           0  Upon the filing of a registration statement to register for resale shares of
              common stock issuable upon the exercise of stock options, which shares are not
              subject to the 180-day lock-up
 
           0  After 90 days from the date of this prospectus, shares saleable under Rule 144
              that are not subject to the 180-day lock-up
 
  17,688,134  After 180 days from the date of this prospectus, the 180-day lock-up is released
              and these shares are saleable under Rule 144 (subject, in some cases, to volume
              limitations), Rule 144(k), or pursuant to a registration statement to register for
              resale shares of common stock issued upon the exercise of stock options
 
  10,396,432  Over 180 days from the date of this prospectus, restricted securities that are
              held for less than one year and are not yet saleable under Rule 144
</TABLE>
    
 
   
    In general, under Rule 144, as currently in effect, a person, or persons
whose shares are required to be aggregated, including an affiliate, who has
beneficially owned shares for at least one year is entitled to sell, within any
three-month period commencing 90 days after the date of this prospectus, a
number of shares that does not exceed the greater of 1% of the then outstanding
shares of common stock, which will be approximately 345,846 shares immediately
after the offering or the average weekly trading volume in the common stock
during the four calendar weeks preceding the date on which notice of such sale
is filed, subject to certain restrictions. In addition, a person who is not
deemed to have been an affiliate of Juno at any time during the 90 days
preceding a sale and who has beneficially owned the shares proposed to be sold
for at least two years would be entitled to sell such shares under Rule 144(k)
without regard to the requirements described above. To the extent that shares
were
    
 
                                       82
<PAGE>
acquired from an affiliate of Juno, such person's holding period for the purpose
of effecting a sale under Rule 144 commences on the date of transfer from the
affiliate.
 
   
    As of the date of this prospectus, options to purchase a total of 3,241,480
shares of common stock are outstanding, of which 420,152 are currently
exercisable. Juno intends to file a Form S-8 registration statement under the
Securities Act shortly after the date of this prospectus to register all shares
of common stock issuable under Juno's option plan. That registration statement
will automatically become effective upon filing. Accordingly, shares covered by
that registration statement will become eligible for sale in the public markets,
subject to vesting restrictions or the lock-up agreement described below. See
"Management--Compensation of Directors" and "--1999 Stock Incentive Plan."
    
 
    All directors and officers and certain stockholders of Juno, holding
substantially all of the outstanding shares of common stock, have agreed,
subject to specified exceptions, that they will not, without the prior written
consent of the representatives of the underwriters, sell or otherwise dispose of
any shares of common stock or options to acquire shares of common stock during
the 180-day period following the date of this prospectus. See "Underwriting."
 
    Juno has agreed not to sell or otherwise dispose of any shares of common
stock during the 180-day period following the date of the prospectus, except
Juno may issue, and grant options to purchase, shares of common stock under the
1999 Stock Incentive Plan. In addition, Juno may issue shares of common stock in
connection with any acquisition of another company if the terms of such issuance
provide that such common stock shall not be resold prior to the expiration of
the 180-day period referenced in the preceding sentence. See "Risk
Factors--Future sales of our common stock may negatively affect our stock
price."
 
    Following this offering, under specified circumstances and subject to
customary conditions, holders of 27,822,751 shares of Juno's outstanding common
stock will have certain demand registration rights with respect to their shares
of common stock, subject to the 180-day lock-up arrangement described above, to
require Juno to register their shares of common stock under the Securities Act,
and certain rights to participate in any future registration of securities by
Juno. Juno is not required to effect more than an aggregate of six demand
registrations on behalf of such holders. Pursuant to the agreement pursuant to
which the registration rights were granted, holders of registrable securities
have agreed to be subject to lock-up periods of not more than 180 days following
the date of this prospectus. See "Description of Capital Stock--Registration
Rights."
 
                                       83
<PAGE>
          UNITED STATES TAX CONSEQUENCES TO NON-UNITED STATES HOLDERS
 
    The following is a general discussion of the material United States federal
income and estate tax consequences of the ownership and disposition of the
common stock applicable to Non-United States Holders of this common stock. For
the purpose of this discussion, a Non-United States Holder is any holder that
for U.S. federal income tax purposes is not a U.S. person. This discussion does
not address all aspects of U.S. federal income and estate taxation that may be
relevant in light of a Non-United States Holder's particular facts and
circumstances, such as being a U.S. expatriate, and does not address any tax
consequences arising under the laws of any state, local or non-U.S. taxing
jurisdiction. Furthermore, the following discussion is based on current
provisions of the Internal Revenue Code of 1986, as amended, and administrative
and judicial interpretations thereof, all as in effect on the date hereof, and
all of which are subject to change, possibly with retroactive effect. Juno has
not and will not seek a ruling from the Internal Revenue Service with respect to
the U.S. federal income and estate tax consequences described below, and as a
result, there can be no assurance that the Internal Revenue Service will not
disagree with or challenge any of the conclusions set forth in this discussion.
For purposes of this discussion, the term U.S. person means:
 
    - a citizen or resident of the United States;
 
    - a corporation, partnership or other entity created or organized in the
      United States or under the laws of the United States or any political
      subdivision thereof;
 
    - an estate whose income is included in gross income for U.S. federal income
      tax purposes regardless of its source; or
 
    - a trust whose administration is subject to the primary supervision of a
      U.S. court and which has one or more U.S. persons who have the authority
      to control all substantial decisions of the trust.
 
DIVIDENDS
 
    If Juno pays a dividend, any dividend paid to a Non-United States Holder of
common stock generally will be subject to U.S. withholding tax either at a rate
of 30% of the gross amount of the dividend or such lower rate as may be
specified by an applicable tax treaty. Dividends received by a Non-United States
Holder that are effectively connected with a U.S. trade or business conducted by
the Non-United States Holder are exempt from such withholding tax. However,
those effectively connected dividends, net of certain deductions and credits,
are taxed at the same graduated rates applicable to U.S. persons.
 
    In addition to the graduated tax described above, dividends received by a
corporate Non-United States Holder that are effectively connected with a U.S.
trade or business of the corporate Non-United States Holder may also be subject
to a branch profits tax at a rate of 30% or such lower rate as may be specified
by an applicable tax treaty.
 
    A Non-United States Holder of common stock that is eligible for a reduced
rate of withholding tax pursuant to a tax treaty may obtain a refund of any
excess amounts currently withheld by filing an appropriate claim for refund with
the IRS.
 
GAIN ON DISPOSITION OF COMMON STOCK
 
    A Non-United States Holder generally will not be subject to U.S. federal
income tax on any gain realized upon the sale or other disposition of his common
stock unless:
 
    - the gain is effectively connected with a U.S. trade or business of the
      Non-United States Holder (which gain, in the case of a corporate
      Non-United States Holder, must also be taken into account for branch
      profits tax purposes);
 
    - the Non-United States Holder is an individual who holds his or her common
      stock as a capital asset (generally, an asset held for investment
      purposes) and who is present in the United States for a period or periods
      aggregating 183 days or more during the calendar year in which the sale or
      disposition occurs and certain other conditions are met; or
 
                                       84
<PAGE>
    - Juno is or has been a "United States real property holding corporation"
      for U.S. federal income tax purposes at any time within the shorter of the
      five-year period preceding the disposition or the holder's holding period
      for its common stock. Juno has determined that it is not and does not
      believe that it will become a "United States real property holding
      corporation" for U.S. federal income tax purposes.
 
BACKUP WITHHOLDING AND INFORMATION REPORTING
 
    Generally, Juno must report annually to the Internal Revenue Service the
amount of dividends paid, the name and address of the recipient, and the amount,
if any, of tax withheld. A similar report is sent to the holder. Pursuant to tax
treaties or other agreements, the Internal Revenue Service may make its reports
available to tax authorities in the recipient's country of resident.
 
    Dividends paid to a Non-United States Holder at an address within the U.S.
may be subject to backup withholding at a rate of 31% if the Non-United States
Holder fails to establish that it is entitled to an exemption or to provide a
correct taxpayer identification number and other information to the payer.
Backup withholding will generally not apply to dividends paid to Non-United
States Holders at an address outside the U.S. on or prior to December 31, 1999
unless the payer has knowledge that the payee is a United States person. Under
recently finalized Treasury Regulations regarding withholding and information
reporting, payment of dividends to Non-United States Holders at an address
outside the U.S. after December 31, 1999 may be subject to backup withholding at
a rate of 31% unless such Non-United States Holder satisfies various
certification requirements.
 
    Under current Treasury Regulations, the payment of the proceeds of the
disposition of common stock to or through the U.S. office of a broker is subject
to information reporting and backup withholding at a rate of 31% unless the
holder certifies its non-U.S. status under penalties of perjury or otherwise
establishes an exemption. Generally, the payment of the proceeds of the
disposition by a Non-United States Holder of common stock outside the U.S. to or
through a foreign office of a broker will not be subject to backup withholding
but will be subject to information reporting requirements if the broker is:
 
   
    - a U.S. person;
    
 
    - a "controlled foreign corporation" for U.S. federal income tax purposes;
      or
 
    - a foreign person 50% or more of whose gross income for certain periods is
      from the conduct of a U.S. trade or business
 
unless the broker has documentary evidence in its files of the holders' non-U.S.
status and certain other conditions are met, or the holder otherwise establishes
an exemption. Neither backup withholding nor information reporting generally
will apply to a payment of the proceeds of a disposition of common stock by or
through a foreign office of a foreign broker not subject to the preceding
sentence.
 
    In general, the recently promulgated final Treasury Regulations, described
above, do not significantly alter the substantive withholding and information
reporting requirements but would alter the procedures for claiming benefits of
an income tax treaty and change the certifications procedures relating to the
receipt by intermediaries of payments on behalf of the beneficial owner of
shares of common stock. Non-United States Holders should consult their tax
advisors regarding the effect, if any, of those final Treasury Regulations on an
investment in the common stock. Those final Treasury Regulations are generally
effective for payments made after December 31, 1999.
 
    Backup withholding is not an additional tax. Rather, the tax liability of
persons subject to backup withholding will be reduced by the amount of tax
withheld. If withholding results in an overpayment of taxes, a refund may be
obtained, provided that the required information is furnished to the Internal
Revenue Service.
 
                                       85
<PAGE>
ESTATE TAX
 
    An individual Non-United States Holder who owns common stock at the time of
his death or had made certain lifetime transfer of an interest in common stock
will be required to include the value of that common stock in such holder's
gross estate for U.S. federal estate tax purposes, unless an applicable estate
tax treaty provides otherwise.
 
    THE FOREGOING DISCUSSION IS A SUMMARY OF THE PRINCIPAL FEDERAL INCOME AND
ESTATE TAX CONSEQUENCES OF THE OWNERSHIP, SALE OR OTHER DISPOSITION OF COMMON
STOCK BY NON-UNITED STATES HOLDERS. ACCORDINGLY, INVESTORS ARE URGED TO CONSULT
THEIR OWN TAX ADVISORS WITH RESPECT TO THE INCOME TAX CONSEQUENCES OF THE
OWNERSHIP AND DISPOSITION OF COMMON STOCK, INCLUDING THE APPLICATION AND EFFECT
OF THE LAWS OF ANY STATE, LOCAL, FOREIGN OR OTHER TAXING JURISDICTION.
 
                                       86
<PAGE>
                                  UNDERWRITING
 
    Subject to the terms and conditions stated in the underwriting agreement
dated the date hereof, each underwriter named below has severally agreed to
purchase and Juno has agreed to sell to each underwriter, the number of shares
set forth below opposite their respective names.
 
<TABLE>
<CAPTION>
                                                                                                       NUMBER OF
UNDERWRITER                                                                                              SHARES
- ----------------------------------------------------------------------------------------------------  ------------
<S>                                                                                                   <C>
Salomon Smith Barney Inc............................................................................
Bear, Stearns & Co. Inc.............................................................................
PaineWebber Incorporated............................................................................
 
                                                                                                      ------------
    Total...........................................................................................     6,500,000
                                                                                                      ------------
                                                                                                      ------------
</TABLE>
 
    The underwriting agreement provides that the obligations of the several
underwriters to purchase the shares included in this offering are subject to
approval of various legal matters by counsel and to various other conditions.
The underwriters are obligated to purchase all the shares, other than those
covered by the over-allotment option described below, if they purchase any of
the shares.
 
    The underwriters, for whom Salomon Smith Barney Inc., Bear, Stearns & Co.
Inc. and PaineWebber Incorporated are acting as representatives, propose to
offer some of the shares directly to the public at the public offering price set
forth on the cover page of this prospectus and some of the shares to various
dealers at the public offering price less a concession not in excess of $    per
share. The underwriters may allow, and those dealers may reallow, a concession
not in excess of $    per share on sales to certain other dealers. If all of the
shares are not sold at the initial offering price, the representatives may
change the public offering price and the other selling terms. The
representatives have advised Juno that the underwriters do not intend to confirm
any sales to any accounts over which they exercise discretionary authority.
 
    Juno has granted to the underwriters an option, exercisable for 30 days from
the date of this prospectus, to purchase up to 975,000 additional shares of
common stock at the public offering price less the underwriting discount. The
underwriters may exercise this option solely for the purpose of covering
over-allotments, if any, in connection with this offering. To the extent the
option is exercised, each underwriter will be obligated, subject to various
conditions, to purchase a number of additional shares approximately
proportionate to each underwriter's initial purchase commitment.
 
   
    Juno, its officers and directors and certain stockholders of Juno, holding
substantially all of the outstanding shares of common stock, have agreed,
subject to specified exceptions, that, for a period of 180 days from the date of
this prospectus, they will not, without the prior written consent of Salomon
Smith Barney Inc., dispose of or hedge any shares of common stock of Juno or any
securities convertible into or exchangeable for common stock. Salomon Smith
Barney Inc. in its sole discretion may release any of the securities subject to
these lock-up agreements at any time without notice.
    
 
   
    At our request, the underwriters have reserved up to five percent (5%) of
the shares of common stock for sale, at the initial public offering price, to
employees and friends of Juno through a directed share program. The number of
shares of common stock available for sale to the general public in the public
offering will be reduced to the extent these persons purchase those reserved
shares.
    
 
   
    Prior to this offering, there has been no public market for the common
stock. Consequently, the initial public offering price for the shares will be
determined by negotiations among Juno and the representatives. Among the factors
to be considered in determining the initial public offering price are
    
 
                                       87
<PAGE>
Juno's record of operations, its current financial condition, its future
prospects, its markets, the economic conditions in and future prospects for the
industry in which Juno competes, its management, and currently prevailing
general conditions in the equity securities markets, including current market
valuations of publicly traded companies considered comparable to Juno. There can
be no assurance, however, that the prices at which the shares will sell in the
public market after this offering will not be lower than the price at which they
are sold by the underwriters or that an active trading market in the common
stock will develop and continue after this offering.
 
   
    Juno's common stock has been approved for quotation on the Nasdaq National
Market under the symbol "JWEB".
    
 
    The following table shows the underwriting discounts and commissions to be
paid to the underwriters by Juno in connection with this offering. These amounts
are shown assuming both no exercise and full exercise of the underwriters'
option to purchase additional shares of common stock.
 
<TABLE>
<CAPTION>
                                                                                                      PAID BY JUNO
                                                                                         --------------------------------------
<S>                                                                                      <C>                <C>
                                                                                            NO EXERCISE        FULL EXERCISE
                                                                                         -----------------  -------------------
Per share..............................................................................      $                   $
Total..................................................................................      $                   $
</TABLE>
 
    In connection with the offering, Salomon Smith Barney Inc., on behalf of the
underwriters, may over-allot, or engage in syndicate covering transactions,
stabilizing transactions and penalty bids. Over-allotment involves syndicate
sales of common stock in excess of the number of shares to be purchased by the
underwriters in the offering, which creates a syndicate short position.
Syndicate covering transactions involve purchases of the common stock in the
open market after the distribution has been completed in order to cover
syndicate short positions. Stabilizing transactions consist of bids or purchases
of common stock made for the purpose of preventing or retarding a decline in the
market price of the common stock while the offering is in progress. Penalty bids
permit the underwriters to reclaim a selling concession from a syndicate member
when Salomon Smith Barney Inc., in covering syndicate short positions or making
stabilizing purchases, repurchases shares originally sold by that syndicate
member. These activities may cause the price of the common stock to be higher
than the price that otherwise would exist in the open market in the absence of
these types of transactions. These transactions may be effected on the Nasdaq
National Market or in the over-the-counter market, or otherwise, and, if
commenced, may be discontinued at any time.
 
    Most of the shares to be sold by Juno in this offering will be sold to U.S.
purchasers, but a limited number of shares may be sold to non-U.S. purchasers.
 
    Certain of the representatives have performed various investment banking and
advisory services for Juno for which they have received customary fees and
expenses. The representatives may, from time to time, engage in transactions
with and perform services for Juno in the ordinary course of their business.
PaineWebber Incorporated acted as Juno's exclusive placement agent in connection
with the private placement of Juno's Series B redeemable convertible preferred
stock in March 1999, in connection with which Juno paid customary placement fees
to PaineWebber.
 
    If and to the extent that any shares are offered or sold in the United
Kingdom, each representative agrees that it:
 
    - will not offer or sell any shares to persons in the United Kingdom except
      to persons whose ordinary activities involve them in acquiring, holding,
      managing or disposing of investments (whether as principal or agent) for
      the purposes of their businesses or in other circumstances which do not
      constitute an offer to the public in the United Kingdom for the purposes
      of the Public Offers of Securities Regulation 1995 (the "Regulations");
 
                                       88
<PAGE>
    - will comply with all applicable provisions of the Regulations and of the
      Financial Services Act 1986 with respect to anything done by it in
      relation to the shares of Common Stock offered hereby in, from or
      otherwise involving the United Kingdom; and
 
    - will only issue or pass on in the United Kingdom any document received by
      it in connection with the issue of these shares if that person is of a
      kind described in Article 11(3) of the Financial Services Act 1986
      (Investment Advertisements) (Exemptions) Order 1996 (as amended) or is a
      person to whom such document may otherwise lawfully be issued or passed
      on.
 
    Juno has agreed to indemnify the underwriters against various liabilities,
including liabilities under the Securities Act of 1933, or to contribute to
payments the underwriters may be required to make in respect of any of those
liabilities.
 
                                       89
<PAGE>
                                 LEGAL MATTERS
 
    The validity of the shares of common stock offered hereby will be passed
upon for Juno by Brobeck, Phleger & Harrison LLP, New York, New York. Legal
matters in connection with the offering will be passed upon for the underwriters
by Cravath, Swaine & Moore, New York, New York.
 
                                    EXPERTS
 
    The consolidated financial statements for Juno, as of December 31, 1997 and
1998 and for each of the three years in the period ended December 31, 1998
included in this prospectus have been so included in reliance on the report of
PricewaterhouseCoopers LLP, independent accountants, appearing elsewhere herein,
upon the authority of said firm as experts in auditing and accounting.
 
                   WHERE YOU CAN FIND ADDITIONAL INFORMATION
 
    Juno has filed with the Securities and Exchange Commission a registration
statement on Form S-1, including exhibits, schedules and amendments filed with
the registration statement, under the Securities Act with respect to the shares
of common stock to be sold in the offering. This prospectus does not contain all
the information set forth in this registration statement. For further
information about Juno and the shares of common stock to be sold in the
offering, please refer to this registration statement. For additional
information, please refer to the exhibits that have been filed with our
registration statement on Form S-1.
 
    You may read and copy all or any portion of the registration statement or
any other information Juno files at the Securities and Exchange Commission's
public reference room at 450 Fifth Street, N.W., Washington, D.C. 20549. You can
request copies of these documents, upon payment of a duplicating fee, by writing
to the Securities and Exchange Commission. Please call the Securities and
Exchange Commission at 1-800-SEC-0330 for further information about the public
reference rooms. Juno's Securities and Exchange Commission filings, including
the registration statement, are also available to you on the Commission's Web
site (http://www.sec.gov).
 
    As a result of the offering, Juno will become subject to the information and
reporting requirements of the Securities Exchange Act of 1934, as amended, and,
in accordance therewith, will file periodic reports, proxy statements and other
information with the Securities and Exchange Commission. Upon approval of the
common stock for the quotation on the Nasdaq National Market, these reports,
proxy and information statements and other information may also be inspected at
the offices of Nasdaq Operations, 1735 K Street, N.W., Washington, D.C. 20006.
 
    Juno intends to furnish its stockholders with annual reports containing
audited consolidated financial statements and make available quarterly reports
for the first three quarters of each year containing unaudited interim
consolidated financial information.
 
                                       90
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
                   INDEX TO CONSOLIDATED FINANCIAL STATEMENTS
 
   
<TABLE>
<CAPTION>
                                                                                                                PAGE
                                                                                                                -----
<S>                                                                                                          <C>
Report of Independent Accountants..........................................................................         F-2
Consolidated Balance Sheets as of December 31, 1997 and 1998 and March 31, 1999 (unaudited)................         F-3
Consolidated Statements of Operations for the years ended December 31, 1996, 1997
  and 1998 and the three months ended March 31, 1998 and 1999 (unaudited)..................................         F-4
Consolidated Statement of Partners' Capital (Deficiency) for the years ended
  December 31, 1996, 1997 and 1998 and Consolidated Statement of Stockholders' Equity (Deficit) for the
  three months ended March 31, 1999 (unaudited)............................................................         F-6
Consolidated Statements of Cash Flows for the years ended December 31, 1996,
  1997 and 1998 and the three months ended March 31, 1998 and 1999 (unaudited).............................         F-7
Notes to Consolidated Financial Statements.................................................................         F-8
</TABLE>
    
 
                                      F-1
<PAGE>
                       REPORT OF INDEPENDENT ACCOUNTANTS
 
To the Board of Directors and Stockholders of
Juno Online Services, Inc.:
 
    In our opinion, the accompanying consolidated balance sheets and the related
consolidated statements of operations, partners' capital (deficiency) and cash
flows present fairly, in all material respects, the financial position of Juno
Online Services, Inc. (formerly Juno Online Services, L.P. & Subsidiary) at
December 31, 1997 and 1998, and the results of their operations and their cash
flows for each of the three years in the period ended December 31, 1998, in
conformity with generally accepted accounting principles. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits. We conducted our audits of these statements in accordance with
generally accepted auditing standards which require that we plan and perform the
audit to obtain reasonable assurance about whether the financial statements are
free of material misstatements. An audit includes examining, on a test basis,
evidence supporting the amounts and disclosures in the financial statements,
assessing the accounting principles used and significant estimates made by
management, and evaluating the overall financial statement presentation. We
believe that our audits provide a reasonable basis for the opinion expressed
above.
 
/s/ PRICEWATERHOUSECOOPERS LLP
New York, New York
March 4, 1999
 
                                      F-2
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
                          CONSOLIDATED BALANCE SHEETS
 
                       (IN THOUSANDS, EXCEPT SHARE DATA)
   
<TABLE>
<CAPTION>
                                                                                                        PRO FORMA
                                                                        DECEMBER 31,       MARCH 31,    MARCH 31,
                                                                    --------------------  -----------  -----------
<S>                                                                 <C>        <C>        <C>          <C>
                                                                      1997       1998        1999         1999
                                                                    ---------  ---------  -----------  -----------
 
<CAPTION>
                                                                                          (UNAUDITED)  (UNAUDITED)
<S>                                                                 <C>        <C>        <C>          <C>
ASSETS
Current assets:
  Cash and cash equivalents.......................................  $  13,770  $   8,152   $  53,165    $  53,165
  Accounts receivable, net of allowance for doubtful accounts of
    $106, $296 and $395 in 1997, 1998 and 1999, respectively......      1,141      2,115       3,205        3,205
  Merchandise inventories, net....................................        769         60          47           47
  Prepaid expenses and other current assets.......................        400        108      11,140       11,140
                                                                    ---------  ---------  -----------  -----------
    Total current assets..........................................     16,080     10,435      67,557       67,557
 
Fixed assets, net.................................................      3,966      4,086       3,876        3,876
Other assets......................................................         87        182         227          227
                                                                    ---------  ---------  -----------  -----------
    Total assets..................................................  $  20,133  $  14,703   $  71,660    $  71,660
                                                                    ---------  ---------  -----------  -----------
                                                                    ---------  ---------  -----------  -----------
LIABILITIES AND PARTNERS' CAPITAL (DEFICIENCY)/STOCKHOLDERS' EQUITY (DEFICIT)
Current liabilities:
  Accounts payable and accrued expenses...........................  $   8,277  $  11,166   $   9,884    $   9,884
  Current portion of capital lease obligations....................        525        450         518          518
  Current portion of senior note..................................         --      1,560       1,560        1,560
  Deferred revenue................................................        351      5,602       7,595        7,595
                                                                    ---------  ---------  -----------  -----------
    Total current liabilities.....................................      9,153     18,778      19,557       19,557
 
Capital lease obligations.........................................        270        609         600          600
Senior note.......................................................         --      7,569       7,252        7,252
Deferred rent.....................................................        206        335         316          316
Deferred revenue..................................................         --         --       1,333        1,333
 
Commitments and contingencies (Note 9)
 
Redeemable convertible preferred stock, $.01 par value;
  Series B: 10,138,716 shares authorized, issued and outstanding
  (liquidation value of $65,000)..................................                            61,853           --
  Series A: 17,684,035 shares authorized, issued and outstanding
  (liquidation value of $79,578)..................................                            79,578           --
 
Partners' capital (deficiency)....................................     10,504    (12,588)
Stockholders' equity (deficit):
  Common stock--$.01 par value; 133,333,334 authorized, 251,229
  issued and outstanding; 28,073,980 issued and outstanding, pro
  forma...........................................................                                 3          281
  Additional paid-in capital......................................                           (95,724)      45,429
  Unearned compensation...........................................                              (691)        (691)
  Accumulated deficit.............................................                            (2,417)      (2,417)
                                                                                          -----------  -----------
    Total shareholders' equity (deficit)..........................                           (98,829)      42,602
                                                                    ---------  ---------  -----------  -----------
    Total liabilities and partners' capital (deficiency)/
      stockholders' equity (deficit)..............................  $  20,133  $  14,703   $  71,660    $  71,660
                                                                    ---------  ---------  -----------  -----------
                                                                    ---------  ---------  -----------  -----------
</TABLE>
    
 
  The accompanying notes are an integral part of these consolidated financial
                                  statements.
 
                                      F-3
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
                     CONSOLIDATED STATEMENTS OF OPERATIONS
 
   
     (IN THOUSANDS, EXCEPT PER LIMITED PARTNERSHIP UNIT AND PER SHARE DATA)
    
 
   
<TABLE>
<CAPTION>
                                                                                              THREE MONTHS ENDED
                                                             YEAR ENDED DECEMBER 31,              MARCH 31,
                                                        ----------------------------------  ----------------------
                                                           1996        1997        1998        1998        1999
                                                        ----------  ----------  ----------  ----------  ----------
<S>                                                     <C>         <C>         <C>         <C>         <C>
                                                                                                 (UNAUDITED)
Revenues:
  Billable services...................................  $        6  $    1,371  $    6,645  $      465  $    5,806
  Advertising and transaction fees....................         127       1,875       6,454       1,228       2,265
  Direct product sales................................           3       5,845       8,595       2,577       1,649
                                                        ----------  ----------  ----------  ----------  ----------
      Total revenues..................................         136       9,091      21,694       4,270       9,720
                                                        ----------  ----------  ----------  ----------  ----------
 
Cost of revenues:
  Billable services...................................          --       1,053       5,606         387       4,678
  Advertising and transaction fees....................         278       1,659       3,725         825       1,080
  Direct product sales................................           3       5,796       7,627       2,426       1,424
                                                        ----------  ----------  ----------  ----------  ----------
      Total cost of revenues..........................         281       8,508      16,958       3,638       7,182
                                                        ----------  ----------  ----------  ----------  ----------
 
Operating expenses:
  Operations, free service............................       5,803      11,075       9,383       2,824       1,846
  Subscriber acquisition..............................       6,993       3,140       5,334       1,453       2,700
  Sales and marketing.................................       4,276      12,593      11,584       4,270       2,312
  Product development.................................       3,741       4,860       7,345       1,835       1,854
  General and administrative..........................       2,172       2,897       2,760         914         704
                                                        ----------  ----------  ----------  ----------  ----------
      Total operating expenses........................      22,985      34,565      36,406      11,296       9,416
                                                        ----------  ----------  ----------  ----------  ----------
      Loss from operations............................     (23,130)    (33,982)    (31,670)    (10,664)     (6,878)
 
Interest income, net..................................         128         243          44          74         111
                                                        ----------  ----------  ----------  ----------  ----------
      Net loss........................................  $  (23,002) $  (33,739) $  (31,626) $  (10,590) $   (6,767)
                                                        ----------  ----------  ----------  ----------  ----------
                                                        ----------  ----------  ----------  ----------  ----------
</TABLE>
    
 
  The accompanying notes are an integral part of these consolidated financial
                                  statements.
 
                                      F-4
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
               CONSOLIDATED STATEMENTS OF OPERATIONS (CONTINUED)
 
   
     (IN THOUSANDS, EXCEPT PER LIMITED PARTNERSHIP UNIT AND PER SHARE DATA)
    
 
   
<TABLE>
<CAPTION>
                                                                                                 THREE MONTHS ENDED
                                                                                                   MARCH 31, 1999
                                                                                        ------------------------------------
                                                                                         TWO MONTHS     MONTH
                                            YEAR ENDED DECEMBER 31,                        ENDED        ENDED
                                       ----------------------------------               FEBRUARY 28,  MARCH 31,
                                          1996        1997        1998                      1999         1999       TOTAL
                                       ----------  ----------  ----------               ------------  ----------  ----------
                                                                              THREE
                                                                             MONTHS
                                                                              ENDED
                                                                            MARCH 31,
                                                                              1998
                                                                           -----------
                                                                           (UNAUDITED)              (UNAUDITED)
<S>                                    <C>         <C>         <C>         <C>          <C>           <C>         <C>
Net loss.............................  $  (23,002) $  (33,739) $  (31,626)  $ (10,590)   $   (4,350)  $   (2,417) $   (6,767)
                                       ----------  ----------  ----------  -----------  ------------  ----------  ----------
                                       ----------  ----------  ----------  -----------  ------------  ----------  ----------
Net loss attributable to common
  stockholders.......................  $  (23,002) $  (33,739) $  (31,626)  $ (10,590)   $   (4,350)  $   (3,589) $   (6,767)
                                       ----------  ----------  ----------  -----------  ------------  ----------  ----------
                                       ----------  ----------  ----------  -----------  ------------  ----------  ----------
Weighted average number of:
  Class A limited partnership
    units............................       3,281      10,500      17,091      16,054        17,684
                                       ----------  ----------  ----------  -----------  ------------
                                       ----------  ----------  ----------  -----------  ------------
  Shares of Common Stock.............                                                                        217
                                                                                                      ----------
                                                                                                      ----------
Basic and diluted net loss per Class
  A limited partnership
  unit...............................  $    (7.01) $    (3.21) $    (1.85)  $   (0.66)   $    (0.25)
                                       ----------  ----------  ----------  -----------  ------------
                                       ----------  ----------  ----------  -----------  ------------
Basic and diluted net loss per
  share..............................                                                                 $   (16.54)
                                                                                                      ----------
                                                                                                      ----------
Pro forma basic and diluted net loss
  per share..........................                          $    (1.85)                                        $    (0.32)
                                                               ----------                                         ----------
                                                               ----------                                         ----------
Weighted average shares outstanding
  used in pro forma basic and diluted
  per share calculation..............                              17,091                                             21,225
                                                               ----------                                         ----------
                                                               ----------                                         ----------
</TABLE>
    
 
  The accompanying notes are an integral part of these consolidated financial
                                  statements.
 
                                      F-5
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
           CONSOLIDATED STATEMENT OF PARTNERS' CAPITAL (DEFICIENCY)/
 
                  STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT)
 
                                 (IN THOUSANDS)
<TABLE>
<CAPTION>
                                          PARTNERS'
                                        CONTRIBUTIONS             COMMON STOCK         ADDITION
                                    ----------------------  ------------------------    PAID-IN       UNEARNED      ACCUMULATED
                                      UNITS      AMOUNT       SHARES       AMOUNT       CAPITAL     COMPENSATION      DEFICIT
                                    ---------  -----------  -----------  -----------  -----------  ---------------  ------------
<S>                                 <C>        <C>          <C>          <C>          <C>          <C>              <C>
Balance, December 31, 1995........        873   $   3,925                                                            $   (3,833)
  Capital contributions...........      4,646      20,906                                                                    --
  Net loss........................         --          --                                                               (23,002)
                                    ---------  -----------                                                          ------------
Balance, December 31, 1996........      5,519      24,831                                                               (26,835)
  Capital contributions...........     10,275      46,247                                                                    --
  Net loss........................         --          --                                                               (33,739)
                                    ---------  -----------                                                          ------------
Balance, December 31, 1997........     15,794      71,078                                                               (60,574)
  Capital contributions...........      1,890       8,500                                                                    --
  Net loss........................         --          --                                                               (31,626)
  Amortization of unearned
    compensation..................         --          --                                                                    34
                                    ---------  -----------                                                          ------------
Balance, December 31, 1998........     17,684      79,578                                                               (92,166)
  Net loss for the period January
    1, 1999 to February 28, 1999
    (unaudited)...................         --          --                                                                (4,350)
  Effect of statutory merger (see
    Note 12)......................    (17,684)    (79,578)          --           --    $ (95,788)     $    (728)         96,516
  Preferred stock accretion
    (unaudited)...................                                  --           --          (53)            --              --
  Issuance of common stock upon
    (unaudited)...................                                 251    $       3          117             --              --
  Net loss for the month ended
    March 31, 1999 (unaudited)....                                  --           --           --             --          (2,417)
  Amortization of unearned
    compensation (unaudited)......                                  --           --           --             37              --
                                    ---------  -----------         ---        -----   -----------         -----     ------------
Balance, March 31, 1999
  (unaudited).....................         --   $      --          251    $       3    $ (95,724)     $    (691)     $   (2,417)
                                    ---------  -----------         ---        -----   -----------         -----     ------------
                                    ---------  -----------         ---        -----   -----------         -----     ------------
 
<CAPTION>
 
                                      TOTAL
                                    ---------
<S>                                 <C>
Balance, December 31, 1995........  $      92
  Capital contributions...........     20,906
  Net loss........................    (23,002)
                                    ---------
Balance, December 31, 1996........     (2,004)
  Capital contributions...........     46,247
  Net loss........................    (33,739)
                                    ---------
Balance, December 31, 1997........     10,504
  Capital contributions...........      8,500
  Net loss........................    (31,626)
  Amortization of unearned
    compensation..................         34
                                    ---------
Balance, December 31, 1998........    (12,588)
  Net loss for the period January
    1, 1999 to February 28, 1999
    (unaudited)...................     (4,350)
  Effect of statutory merger (see
    Note 12)......................    (79,578)
  Preferred stock accretion
    (unaudited)...................        (53)
  Issuance of common stock upon
    (unaudited)...................        120
  Net loss for the month ended
    March 31, 1999 (unaudited)....     (2,417)
  Amortization of unearned
    compensation (unaudited)......         37
                                    ---------
Balance, March 31, 1999
  (unaudited).....................  $ (98,829)
                                    ---------
                                    ---------
</TABLE>
 
  The accompanying notes are an integral part of these consolidated financial
                                  statements.
 
                                      F-6
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
 
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                 THREE MONTHS
                                                             YEAR ENDED DECEMBER 31,           ENDED MARCH 31,
                                                        ----------------------------------  ----------------------
                                                           1996        1997        1998        1998        1999
                                                        ----------  ----------  ----------  ----------  ----------
                                                                                                 (UNAUDITED)
<S>                                                     <C>         <C>         <C>         <C>         <C>
Cash flows from operating activities:
  Net loss............................................  $  (23,002) $  (33,739) $  (31,626) $  (10,590) $   (6,767)
  Adjustments to reconcile net loss to net cash used
    in operating activities:
    Depreciation and amortization.....................          --         161       2,438         563         567
    Amortization of deferred rent.....................          --         244         157         195         (16)
    Amortization of unearned compensation.............          --          --          34          --          37
    Changes in operating assets and liabilities:
      Accounts receivable.............................        (121)     (1,020)       (974)       (249)     (1,090)
      Merchandise inventories.........................          --        (769)        709         437          13
      Prepaid expenses and other current assets.......         (90)       (214)        292         146     (11,032)
      Accounts payable and accrued expenses...........       6,834       1,401       2,861      (2,055)     (1,285)
      Deferred revenue................................           6         345       5,251       1,928       3,326
                                                        ----------  ----------  ----------  ----------  ----------
        Net cash used in operating activities.........     (16,373)    (33,591)    (20,858)     (9,625)    (16,247)
                                                        ----------  ----------  ----------  ----------  ----------
Cash flows from investing activities:
  Purchases of fixed assets...........................          --      (3,270)     (1,942)     (1,248)       (105)
  Proceeds from sale of fixed assets..................          --          --         402          --          --
  Other assets........................................          --         (87)        (95)         (3)        (45)
                                                        ----------  ----------  ----------  ----------  ----------
        Net cash used in investing activities.........          --      (3,357)     (1,635)     (1,251)       (150)
                                                        ----------  ----------  ----------  ----------  ----------
Cash flows from financing activities:
  Payments on capital lease obligations...............          --         (62)       (754)       (125)       (193)
  Proceeds from senior note...........................          --          --      10,000      10,000          --
  Payments on senior note.............................          --          --        (871)         --        (317)
  Net proceeds from issuance of redeemable convertible
    preferred stock...................................          --          --          --          --      61,800
  Capital contributions...............................      16,971      50,182       8,500       3,500          --
  Proceeds from issuance of common stock..............          --          --          --          --         120
                                                        ----------  ----------  ----------  ----------  ----------
        Net cash provided by financing activities.....      16,971      50,120      16,875      13,375      61,410
                                                        ----------  ----------  ----------  ----------  ----------
        Net increase (decrease) in cash and cash
          equivalents.................................         598      13,172      (5,618)      2,499      45,013
 
Cash and cash equivalents, beginning of period........          --         598      13,770      13,770       8,152
                                                        ----------  ----------  ----------  ----------  ----------
Cash and cash equivalents, end of period..............  $      598  $   13,770  $    8,152  $   16,269  $   53,165
                                                        ----------  ----------  ----------  ----------  ----------
                                                        ----------  ----------  ----------  ----------  ----------
 
Supplemental disclosure of cash flow information:
  Cash paid for interest..............................  $       --  $      127  $      496  $       28  $      145
 
Supplemental schedule of noncash investing and
  financing activities:
  Accretion of preferred stock........................  $       --  $       --  $       --  $       --  $       53
  Capital lease obligations incurred for network
    equipment.........................................          --         857       1,018         878         252
  Notes received for issuance of partnership units....       3,935          --          --          --          --
</TABLE>
 
  The accompanying notes are an integral part of these consolidated financial
                                  statements.
 
                                      F-7
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
1.  ORGANIZATION AND BUSINESS
 
    Juno Online Services, Inc. is the surviving entity of a Statutory Merger
with Juno Online Services, L.P. This merger of entities under common control was
effected on March 1, 1999 (see Note 12, Subsequent Events).
 
    Juno Online Services, L.P. was organized as a Delaware limited partnership
on June 30, 1995. The consolidated financial statements include the accounts of
Juno Online Services, L.P. and its wholly owned subsidiary, Juno Online
Services, Inc. (collectively, the "Company" or "Juno"). Juno Online Services,
Inc. was incorporated in the State of Delaware on July 2, 1996, and was a wholly
owned subsidiary from February 12, 1997 through March 1, 1999, the date of the
Statutory Merger. All significant intercompany accounts and transactions have
been eliminated in consolidation.
 
    The Company is a provider of Internet-related services throughout the United
States. The Company offers several levels of service, ranging from basic dial-up
Internet e-mail -- which is provided to the end user for free -- to billable
subscription services, including full access to the World Wide Web. Revenues are
derived primarily from the subscription fees charged for billable subscription
services, from the sale of advertising, and from the direct sale of products to
the Company's subscribers.
 
    The Company has experienced operating losses since its inception. Such
losses are due to the Company's efforts to maximize the number of subscribers to
both its free basic e-mail service and, more recently, its billable subscription
services, and to its development of computer systems and related infrastructure
that could be rapidly expanded to accommodate additional users. Juno Online
Services, Inc. expects that it will continue to incur net losses as it expends
substantial additional resources in an attempt to rapidly increase its market
share. There can be no assurance that Juno Online Services, Inc. will achieve or
sustain profitability or positive cash flow from its operations.
 
2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
USE OF ESTIMATES
 
    The Company's consolidated financial statements are prepared in accordance
with generally accepted accounting principles, which require management to use
its judgment in making certain estimates and assumptions that affect the
reported amounts of assets and liabilities and disclosures of contingent
liabilities at the dates of the financial statements and the reported amounts of
operating revenues and expenses during the reporting periods. It is expected
that such estimates will differ to some extent from the amounts ultimately
realized due to uncertainties inherent in any such estimation process.
 
UNAUDITED INTERIM FINANCIAL STATEMENTS
 
    The financial statements as of March 31, 1999 and for the three months ended
March 31, 1998 and 1999 are unaudited. In the opinion of management, this
unaudited information has been prepared substantially on the same basis as the
audited consolidated financial statements and all necessary adjustments,
consisting only of normal recurring adjustments, have been included in the
amounts presented to present fairly the unaudited quarterly results. The results
for a quarter are not necessarily indicative of the results for any future
period.
 
                                      F-8
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
CASH AND CASH EQUIVALENTS
 
    The Company considers all highly liquid investments with an original
maturity of three months or less to be cash equivalents. Cash balances at
December 31, 1998 consisted of bank deposits with one institution and investment
grade overnight securities. The Company reviews the credit ratings of its
banking institution on a regular basis.
 
REVENUE RECOGNITION
 
   
    Billable services revenues are recognized over the period services are
provided. In 1997, billable services revenues consisted primarily of technical
support fees. In 1998, billable services revenues consisted primarily of fees
charged for our billable subscription services and technical support fees.
    
 
   
    Advertising and transaction fees are derived both from advertising and
strategic marketing alliance contracts in which the Company receives a fee for
displaying impressions (a single display of an advertisement to a subscriber) or
is compensated for generating leads or transactions. Advertising contracts are
generally structured to provide a fixed number of impressions on a
fee-per-impression basis without regard to a specific period of time. These
contracts tend to be short-term in nature and the Company's obligations are
typically fulfilled over a period of a few months. Strategic marketing alliance
contracts are generally structured over longer specific periods of time, ranging
from a few months to several years. Strategic marketing alliance contracts
generally provide the Company with guaranteed payments as advances against
various forms of revenue-sharing for generating leads or transactions, or for
producing and displaying impressions.
    
 
   
    Revenues generated by advertising and strategic marketing alliance contracts
are generally recognized as earned, provided that the Company does not have any
significant remaining obligations and the collection of the resulting receivable
is probable. Remaining obligations include the fulfillment of a fixed or
guaranteed minimum number of impressions to be displayed or the achievement of
performance targets. The earnings process typically coincides with when the
impressions are displayed, leads or transactions are generated, or services
performed. To the extent that guaranteed minimum impressions or performance
targets exist for a specific time period, revenue is recognized at the lesser of
the ratio of the obligations delivered over total obligations, or on a
straight-line basis for the term of the contract. To the extent that guaranteed
minimum impressions or performance targets exist and are not met, the Company
defers recognition of the corresponding revenues until the remaining guaranteed
impressions are displayed or performance targets are achieved.
    
 
   
    Costs associated with advertising and strategic marketing alliance
contracts, principally transmission, development, production and campaign
management costs, are expensed as incurred.
    
 
    Revenues from direct product sales and delivery fees are recognized upon
shipment of products to subscribers.
 
    Revenues are reported net of a provision for sales allowances. Sales
allowances and bad debt expenses were $9, $233 and $616 in 1996, 1997 and 1998,
respectively.
 
                                      F-9
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    Deferred revenue consists of monthly and annual prepaid subscriber fees
related to billable subscription services and advertising and transaction fees
billed in advance of the performance of all or a portion of the related service.
 
MERCHANDISE INVENTORIES
 
    Inventories, principally microcomputers and computer hardware and software,
are stated at the lower of cost (on a first-in, first-out basis) or market. As
of December 31, 1997 and 1998, merchandise inventories held in connection with
the Company's direct product sales initiative are presented net of reserves of
$150 and $11, respectively, for obsolete, slow moving and excess inventories.
 
FIXED ASSETS
 
    Fixed assets are stated at cost, net of accumulated depreciation and
amortization, which is calculated on a straight-line basis over lives ranging
from 3 to 5 years or, for leasehold improvements, over the life of the lease, if
shorter.
 
LONG-LIVED ASSETS
 
    The Company periodically evaluates the net realizable value of long-lived
assets, including fixed assets and other assets, relying on a number of factors
including operating results, business plans, economic projections and
anticipated future cash flows. In addition, the Company's evaluation considers
nonfinancial data such as market trends, product and development cycles, and
changes in management's market emphasis. An impairment in the carrying value of
an asset is recognized when the expected future operating cash flows derived
from the asset are less than its carrying value.
 
ADVERTISING AND SUBSCRIBER ACQUISITION COSTS
 
    The Company accounts for advertising and subscriber acquisition costs
pursuant to Statement of Position ("SOP") 93-7, "Reporting on Advertising
Costs." Accordingly, the Company expenses all costs of advertising as incurred.
Advertising expenses for 1996, 1997 and 1998 were $6,178, $1,878 and $2,389,
respectively.
 
MAINTENANCE AND REPAIRS
 
    These costs are charged to expense as incurred. Major renewals, betterments
and additions are capitalized.
 
PRODUCT DEVELOPMENT COSTS
 
    The Company's product offerings are comprised of various features which
contribute to the overall functionality and are delivered through client-side
software, server-side software, and database applications which have been
principally developed internally. Software development costs include direct
labor and related overhead for software produced by the Company and the cost of
software licensed from third parties. All costs in the software development
process which are classified as research and development are expensed as
incurred until technological feasibility has been established,
 
                                      F-10
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
at which time such costs are capitalized until the software is generally
available. To date, the establishment of technological feasibility of the
Company's products and the general availability of such software have
substantially coincided. As a result, software development costs that qualify
for capitalization have been insignificant and therefore, the Company has not
capitalized any software development costs.
 
OPTION PLAN
 
    On January 1, 1996, the Company adopted Statement of Financial Accounting
Standard ("SFAS") No. 123, "Accounting for Stock-Based Compensation" ("SFAS
123"), which permits entities to recognize as expense over the vesting period
the fair value of all equity-based awards on the date of grant. Alternatively,
SFAS 123 allows entities to continue to apply the provisions of Accounting
Principles Board ("APB") Opinion No. 25, "Accounting for Stock Issued to
Employees," and provide pro forma disclosures for employee unit option grants
made in 1997 and future years as if the fair-value based method defined in SFAS
123 had been applied. The Company has elected to continue to apply the
provisions of APB Opinion No. 25 and apply the pro forma disclosure provisions
of SFAS 123.
 
INCOME TAXES
 
    U.S. federal and state income taxes have not been provided because the
partners report their respective distributive share of the Company's income or
loss on their respective returns.
 
FINANCIAL INSTRUMENTS AND CONCENTRATION OF CREDIT RISK
 
    The carrying values of the Company's cash and cash equivalents, accounts
receivable and accounts payable approximate fair value. Financial instruments
that potentially subject the Company to concentration of credit risk consist
principally of cash investments and trade receivables. The Company has limited
its cash investments to investment grade overnight securities. Credit is
extended to trade customers based on an evaluation of their financial condition.
The Company performs ongoing credit evaluations of its trade customers and
maintains an allowance for doubtful accounts. Credit risk with regard to the
sale of products and billable subscription services is mitigated by the
requirement of credit cards for purchases.
 
RECLASSIFICATION
 
    Certain amounts in the prior year financial statements have been
reclassified to conform to the current year presentation.
 
RECENT ACCOUNTING PRONOUNCEMENTS
 
    In June 1998, the Financial Accounting Standards Board ("FASB") issued SFAS
No. 133, "Accounting for Derivative Instruments and Hedging Activities" ("SFAS
133"). SFAS 133 establishes new accounting and reporting standards for
derivative financial instruments and for hedging activities. As of December 31,
1998, the Company had no derivative instruments.
 
                                      F-11
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
2.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    In June 1997, FASB issued SFAS No. 131 "Disclosures about Segments of an
Enterprise and Related Information" ("SFAS 131"). SFAS 131 establishes standards
for the way that public business enterprises report information about operating
segments in annual financial statements and requires that those enterprises
report selected information about operating segments in interim financial
reports issued. The statement has not had an impact on the Company's financial
statement disclosures as its financial statements reflect how the "key operating
decision makers" view the business. Accordingly, the financial statements are
presented as a single segment.
 
    In June 1997, FASB issued SFAS No. 130, "Reporting Comprehensive Income"
("SFAS 130"). SFAS 130 establishes standards for the reporting and display of
comprehensive income and its components in the financial statements. SFAS 130 is
effective for years beginning after December 15, 1997. The statement has not had
an impact on the Company's financial statements as the Company has no other
comprehensive income to report.
 
   
    In February 1997, FASB issued SFAS No. 128 "Earnings Per Share" ("SFAS
128"). SFAS 128 replaced primary and fully diluted earnings per share with basic
and diluted earnings per share. The statement makes certain modifications to the
earnings per share calculations defined in APB Opinion No. 15. SFAS 128 is
effective for years ending after December 31, 1997. The Company has adopted SFAS
128. Details pertaining to the earnings (loss) per share presentation and
calculation are included in Note 3 Earnings Per Share.
    
 
    In March 1998, the American Institute of Certified Public Accountants issued
SOP 98-1 "Accounting for the Costs of Computer Software Developed or Obtained
for Internal Use" ("SOP 98-1") which provides guidance on accounting for the
costs of computer software developed or obtained for internal use. The
pronouncement identifies the characteristics of internal use software and
provides guidance on new cost recognition principles. SOP 98-1 is effective for
financial statements for fiscal years beginning after December 15, 1998. The
adoption of SOP 98-1 will not have a significant impact on the Company's
consolidated financial position, results of operations, and cash flows.
 
                                      F-12
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
3.  EARNINGS PER SHARE
    
 
   
    The following table sets forth the computation of basic and diluted loss per
share.
    
 
   
<TABLE>
<CAPTION>
                                                                                    THREE MONTHS ENDED MARCH 31, 1999
                                                                              ---------------------------------------------
                                                                                 TWO MONTHS
                               YEAR ENDED DECEMBER 31,         THREE MONTHS         ENDED          MONTH ENDED
                         -----------------------------------      ENDED         FEBRUARY 28,        MARCH 31,
                           1996        1997         1998        MARCH 31,           1999              1999          TOTAL
                         ---------  -----------  -----------       1998       -----------------  ---------------  ---------
                                                              --------------
                                                               (UNAUDITED)                     (UNAUDITED)
<S>                      <C>        <C>          <C>          <C>             <C>                <C>              <C>
Numerator:
  Net loss.............  $ (23,002) $   (33,739)     (31,626)  $    (10,590)     $    (4,350)       $  (2,417)    $  (6,767)
  Accrued dividend on
    preferred stock....                                                                                (1,119)
  Preferred stock
    accretion..........                                                                                   (53)
                         ---------  -----------  -----------  --------------  -----------------  ---------------  ---------
  Net loss available to
    common
    stockholders.......  $ (23,002) $   (33,739) $   (31,626)  $    (10,590)     $    (4,350)       $  (3,589)    $ $(6,767)
                         ---------  -----------  -----------  --------------  -----------------  ---------------  ---------
                         ---------  -----------  -----------  --------------  -----------------  ---------------  ---------
Denominator:
  Weighted average
    number of:
    Class A limited
      partnership
      units............  3,280,513   10,500,233   17,091,436     16,054,399       17,684,035
                         ---------  -----------  -----------  --------------  -----------------
                         ---------  -----------  -----------  --------------  -----------------
    Shares of Common
      Stock............                                                                               216,911
                                                                                                 ---------------
                                                                                                 ---------------
    Basic and diluted
      net loss per
      Class A limited
      partnership
      unit.............  $   (7.01) $     (3.21) $     (1.85)  $      (0.66)     $     (0.25)
    Basic and diluted
      net loss per
      share............                                                                             $  (16.54)
                                                                                                 ---------------
                                                                                                 ---------------
</TABLE>
    
 
   
    Net loss per share for the three months ended March 31, 1999 is calculated
separately for the periods prior and subsequent to the March 1999 statutory
merger.
    
 
                                      F-13
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
3.  EARNINGS PER SHARE (CONTINUED)
    
   
    The pro forma information regarding net loss per share and weighted average
shares outstanding set forth below gives effect to the treatment of Class A
limited partnership units as shares of common stock and the conversion of Series
B Redeemable Convertible Preferred Stock for the period following the March 1999
statutory merger.
    
 
   
<TABLE>
<CAPTION>
                                                                                   THREE
                                                                                MONTHS ENDED
                                                               YEAR ENDED      MARCH 31, 1999
                                                            DECEMBER 31, 1998  --------------
                                                            -----------------   (UNAUDITED)
<S>                                                         <C>                <C>
Numerator:
  Net loss................................................    $     (31,626)    $     (6,767)
                                                            -----------------  --------------
                                                            -----------------  --------------
Denominator:
  Weighted average number of:
      Shares of common stock..............................                            74,746
      Class A limited partnership units treated as shares
        of common stock...................................       17,091,436
  Redeemable Convertible Preferred Stock treated as shares
    of common stock:
      Series B............................................                         3,466,228
      Series A (Class A limited partnership units prior to
        March 1, 1999)....................................                        17,684,035
                                                            -----------------  --------------
      Denominator for pro forma basic and diluted net loss
        per share.........................................       17,091,436       21,225,009
                                                            -----------------  --------------
                                                            -----------------  --------------
Pro forma basic and diluted net loss per share............    $       (1.85)    $      (0.32)
                                                            -----------------  --------------
                                                            -----------------  --------------
</TABLE>
    
 
   
4.  FIXED ASSETS
    
 
    Fixed assets consists of the following:
 
<TABLE>
<CAPTION>
                                                                                 DECEMBER 31,
                                                                             --------------------
<S>                                                                          <C>        <C>
                                                                               1997       1998
                                                                             ---------  ---------
Computers, network equipment and software..................................  $   3,225  $   5,672
Furniture and office equipment.............................................        197        187
Leasehold improvements.....................................................        705        772
                                                                             ---------  ---------
    Subtotal...............................................................      4,127      6,631
Accumulated depreciation and amortization..................................       (161)    (2,545)
                                                                             ---------  ---------
    Total..................................................................  $   3,966  $   4,086
                                                                             ---------  ---------
                                                                             ---------  ---------
</TABLE>
 
    Included in fixed assets is equipment acquired under capital leases,
principally network equipment, of $977 and $1,995 as of December 31, 1997 and
1998, less accumulated amortization of $13 and $859, respectively.
 
                                      F-14
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
5.  ACCOUNTS PAYABLE AND ACCRUED EXPENSES
    
 
    Accounts payable and accrued expenses consist of the following:
 
<TABLE>
<CAPTION>
                                                                               DECEMBER 31,
                                                                           --------------------
<S>                                                                        <C>        <C>
                                                                             1997       1998
                                                                           ---------  ---------
Trade accounts payable...................................................  $   2,067  $   2,315
Personnel and related expenses...........................................      3,511      4,038
Telecommunications services..............................................        728      1,210
Customer service expenses................................................        230        857
Marketing expenses.......................................................        182        756
Other....................................................................      1,559      1,990
                                                                           ---------  ---------
    Total................................................................  $   8,277  $  11,166
                                                                           ---------  ---------
                                                                           ---------  ---------
</TABLE>
 
   
6.  RELATED PARTY TRANSACTIONS
    
 
    The Company is affiliated with a group of entities that are under control of
or are subject to substantial influence by D. E. Shaw & Co., Inc. ("DESCO,
Inc.") which is the general partner of the Company's general partner, D. E. Shaw
Development, L.P. The affiliated entity with which the Company interacts most
(due to that affiliate's role as management company for many of the entities) is
D. E. Shaw & Co., L.P. ("DESCO, L.P."). DESCO, Inc. is also the general partner
of DESCO, L.P. (Prior to March 1997, DESCO, L.P. was the general partner of D.
E. Shaw Development, L.P.) DESCO, L.P. became a limited partner of the Company
in October 1997.
 
    During 1996 substantially all of the Company's personnel, management and
overhead services were provided by DESCO, L.P., the costs of which were
allocated to the Company on the basis of various metrics as determined by DESCO,
L.P. During that period, all of the individuals working on Company initiatives
were employed by DESCO, L.P. On February 22, 1997, substantially all of the
individuals working on Company initiatives were transferred to, and became
employees of, the Company's wholly owned subsidiary, Juno Online Services, Inc.
Subsequently, DESCO, L.P. continued to provide certain administrative and
support services to the Company, albeit in a decreased capacity. Effective
January 1, 1998, the Company entered into services agreements with DESCO, L.P.
and an affiliate of DESCO, L.P. for the provision of certain of these services
at fixed rates.
 
    In addition, the Company entered into a services agreement with an
India-based affiliate of DESCO, L.P.  DESCO, L.P. is paid a fixed monthly fee
for engineering and operations services rendered, and is reimbursed for
incidental expenses.
 
                                      F-15
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
6.  RELATED PARTY TRANSACTIONS (CONTINUED)
    
    These agreements extend on a month-to-month basis. Either party may
terminate the agreements for convenience at any time upon ninety days written
notice. The aggregate amounts and nature of the expenditures made by DESCO, L.P.
on behalf of the Company were as follows:
 
<TABLE>
<CAPTION>
                                                                            1996       1997       1998
                                                                          ---------  ---------  ---------
<S>                                                                       <C>        <C>        <C>
India-based engineering and operations expense..........................  $      --  $      --  $   1,454
Personnel and related expenses..........................................      5,499      1,561        521
Depreciation and leased equipment.......................................      1,140        617         --
Occupancy costs.........................................................        484        784        338
Other operating expenses................................................      7,952      1,362        375
                                                                          ---------  ---------  ---------
      Total.............................................................  $  15,075  $   4,324  $   2,688
                                                                          ---------  ---------  ---------
                                                                          ---------  ---------  ---------
</TABLE>
 
    The Company's balance sheet reflects $96 due from DESCO, L.P. under the
caption "Prepaid expenses and other current assets" at December 31, 1997.
 
ASSET PURCHASES AND TRANSFERS
 
    Historically, the Company has utilized certain fixed assets, including
leasehold improvements, computers, telecommunications and server hardware, owned
by DESCO, L.P., the expense of which has been allocated to the Company.
Beginning in July 1997, substantially all new acquisitions of fixed assets have
been made by the Company directly.
 
    In 1998, the Company transferred fixed assets with a net book value of $402
to DESCO, L.P.
 
    Pursuant to an asset purchase agreement dated December 31, 1997, the Company
acquired various fixed assets from DESCO, L.P. These assets, principally
computers, equipment and network software, were originally purchased by DESCO,
L.P. on behalf of the Company. The total purchase price of the assets was
$1,202.
 
GENERAL PARTNER FEES AND OTHER COMPENSATION
 
    As compensation for managing the affairs of the Company, the Company's
general partner is entitled to a monthly management fee equal to one-twelfth of
one percent of the aggregate value of all outstanding limited partnership Units
(or other property into which such Units have been converted) as of the most
recent Valuation Event (as specified in the limited partnership agreement, as
amended). In 1996, 1997 and 1998, the Company's general partner elected to waive
management fees of $49, $81 and $285, respectively.
 
                                      F-16
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
7.  OBLIGATIONS UNDER CAPITAL LEASES
    
 
    The following is a schedule, by year, of future minimum lease payments under
capital leases, together with the present value of the minimum lease payments as
of December 31, 1998:
 
<TABLE>
<CAPTION>
YEAR ENDING DECEMBER 31,
- -------------------------------------------------------------------------------------
<S>                                                                                    <C>
1999.................................................................................  $     526
2000.................................................................................        460
2001.................................................................................        134
2002.................................................................................         40
2003.................................................................................         33
                                                                                       ---------
      Total minimum lease payments...................................................      1,193
Less: Amount representing interest...................................................       (134)
                                                                                       ---------
      Present value of the minimum lease payments....................................  $   1,059
                                                                                       ---------
                                                                                       ---------
</TABLE>
 
    Included in total minimum lease payments above are $164 of obligations under
capital leases for network equipment that were assigned to the Company by DESCO,
L.P. As the original lessee, DESCO, L.P. remains responsible under these lease
agreements in the event of a default by the Company.
 
   
8.  SENIOR NOTE
    
 
    On March 31, 1998, the Company borrowed $10,000 from D. E. Shaw Securities
Group, L.P. ("Shaw Securities"), pursuant to an unsecured Senior Note (the
"Senior Note"). Shaw Securities, whose general partner is DESCO, L.P. is an
affiliate of the Company. The Senior Note, as amended, bears interest at the
Federal Funds Rate plus 0.375% (4.445% at December 31, 1998) and matures on
December 31, 2000 unless extended by Shaw Securities. The Senior Note requires
mandatory prepayments equal to 10% of certain distributions from Shaw Securities
to DESCO, L.P. As of March 1, 1999, DESCO, L.P. and Juno modified certain
support arrangements. As modified, these arrangements provide that Juno shall be
indebted to DESCO, L.P. under terms substantially similar to the Senior Note in
the event that Juno fails to make such mandatory prepayments and DESCO, L.P.
makes such payments on Juno's behalf. Under certain circumstances, DESCO, L.P.
shall receive Series B redeemable convertible preferred stock at $6.41 per share
in return for making such support payments. The Senior Note shall be repaid in
full at completion of an initial public offering by the Company registered under
the U.S. Securities Act of 1933, as amended. The Company may prepay the Senior
Note at any time, in whole or in part, without premium or penalty. Pursuant to
the Senior Note, the Company may not incur any additional indebtedness in an
aggregate principal amount greater than $1,000, excluding the acquisition of
fixed assets in the ordinary course of business.
 
    The Company's interest expense under the Senior Note was approximately $418
for the year ended December 31, 1998.
 
                                      F-17
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
9.  COMMITMENTS AND CONTINGENCIES
    
 
COMMITMENTS
 
    The Company has entered into various non-cancellable operating leases for
equipment. DESCO, L.P. has also entered into a leasing arrangement for office
space used by the Company. Substantially all of the Company's operations are
located in a single location that is leased by DESCO, L.P. The Company, which
benefits from the use of this office space, has agreed to assume performance of
DESCO, L.P.'s payment obligations under the lease to the extent the Company
occupies such office space. Minimum lease payments below include $1,875 related
to this arrangement with DESCO, L.P. Minimum lease payments as of December 31,
1998 under these operating leases and this arrangement are as follows:
 
<TABLE>
<CAPTION>
YEAR ENDING DECEMBER 31,
- -------------------------------------------------------------------------------------
<S>                                                                                    <C>
1999.................................................................................  $   1,993
2000.................................................................................        110
                                                                                       ---------
      Total minimum lease payments...................................................  $   2,103
                                                                                       ---------
                                                                                       ---------
</TABLE>
 
    The Company's rental expense under operating leases in the years ended
December 31, 1996, 1997 and 1998, was approximately $290, $889, and $1,070,
respectively.
 
    The Company has committed to minimum usage levels for certain
telecommunications services. The remaining commitments are $570 and $90 for the
years ending December 31, 1999 and 2000, respectively. Telecommunications
services expense for the years ended December 31, 1996, 1997 and 1998 was
$2,655, $7,155 and $8,772, respectively.
 
CONTINGENCIES
 
    Various claims and actions have been asserted or threatened against the
Company in the ordinary course of business. There are no threats, asserted
claims or actions, the outcome of which, in the opinion of management, would
have a materially adverse effect on the Company's consolidated financial
position, results of operations, and cash flows, taken as a whole.
 
   
10.  PARTNERS' CAPITAL
    
 
    Interests in Juno Online Services, L.P., which take the form of Units, are
comprised of Class A Units and Class B Units. Class A Units are senior to Class
B Units, and have several preferential attributes, including (i) a contingent
priority distribution feature that provides holders of Class A Units, at the end
of a Fiscal Period (as specified in the limited partnership agreement, as
amended), a priority distribution of net profits equivalent to a $0.41 per Unit
annual return (but only if the Company's general partner elects to declare a
distribution with respect to such Fiscal Period), and (ii) a preference upon
liquidation equal to $4.50 per Class A Unit (less certain distributions) plus
any declared and unpaid priority distributions. There have been no priority
distributions declared by the Company's general partner to date. The preference
payment upon liquidation is payable before proceeds of a liquidation are applied
to other holders of Units. As of December 31, 1998, an aggregate of 17,768,035
Class A Units were issued and outstanding. As of December 31, 1998, although
Class B Units are subject to the Company's 1997 Class B Unit Option/Issuance
Plan, no Class B Units had been issued.
 
                                      F-18
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
11.  EMPLOYEE OPTION PLAN
    
 
    The Company's 1997 Class B Unit Option/Issuance Plan (the "1997 Plan")
provides the Company's general partner the right to increase or decrease the
number of Class B Units that may be issued under the Plan. The number of Class B
Units issuable under the plan was increased to 3,366,667 in October 1998. Under
the 1997 Plan, non-qualified options to issue Units may be granted to all
employees of the Company and consultants as an incentive to remain in the
Company's service, among other reasons. The exercise price per Unit shall not be
less than 85% of the fair market value on the option grant date. For any 10%
owners of the Company, the exercise price per Unit shall not be less than 110%
of the fair market value on the option grant date. In general, the options vest
at a rate of 20% annually on the anniversary of the grant date and expire 10
years from the date of grant. However, in general, no options may be exercised
prior to the earlier of (i) the date that the Company converts to a corporate
form of organization or (ii) the expiration of the three year period measured
from the grant date. The initial date of grant was April 2, 1997. A grandfather
provision was made by the 1997 Plan Administrator to enable the commencement of
vesting, for employees involved with the Company prior to January 1, 1997, to
begin on the later of their employment date or January 1, 1996. For the year
ended December 31, 1998, the Company recorded unearned compensation of $762 for
options issued below deemed fair value for accounting purposes of the Company's
Class B Units. This amount is being charged to compensation expense over a five
year period (the vesting period of the options).
 
    The following information relates to options issued to purchase Class B
Units under the 1997 Plan:
 
<TABLE>
<CAPTION>
                                                                  CLASS B    WEIGHTED AVERAGE
                                                                   UNITS      PRICE PER UNIT
                                                                 ----------  -----------------
<S>                                                              <C>         <C>
Outstanding January 1, 1997....................................          --      $       -
  Granted......................................................   1,495,546           0.45
  Exercised....................................................          --              -
  Forfeited....................................................    (135,443)          0.45
                                                                 ----------
Outstanding January 1, 1998....................................   1,360,103           0.45
  Granted......................................................   1,577,437           0.84
  Exercised....................................................          --              -
  Forfeited....................................................    (353,171)          0.45
                                                                 ----------
Outstanding December 31, 1998..................................   2,584,369           0.67
                                                                 ----------
                                                                 ----------
</TABLE>
 
    On December 31, 1998, the exercise price of outstanding options ranged from
$0.45 to $2.70. The weighted average remaining contractual life was 9.0 years.
 
    The Company accounts for its equity-based compensation in accordance with
APB Opinion No. 25 and its related interpretations.
 
    Had the Company's equity-based employee compensation been determined by the
fair-value based method of SFAS 123, the Company's net loss on a pro-forma basis
for the years ended December 31, 1996, 1997 and 1998 would have been $(23,002),
$(33,773) and $(31,723), respectively.
 
    The Company has used the minimum value method to value the options issued.
The weighted average fair value of the options on the dates granted during 1997
and 1998 were $0.22 and $0.23, respectively. The fair value was based on a risk
free interest rate of 5%, zero dividend yield, and an expected life of 7 years.
 
                                      F-19
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
12.  EMPLOYEE BENEFIT PLAN
    
 
    The Company is a participating employer in a tax-qualified retirement plan
(the "Savings Plan") under Section 401(k) of the Internal Revenue Code. Under
the Savings Plan, participating employees may defer a portion of their pre-tax
earnings, up to the Internal Revenue Service annual contribution limit. The
Company matches 50% of each employee's contribution up to a maximum of 6% of the
employee's eligible earnings. In 1996, 1997 and 1998 the Company match was $0,
$159 and $238, respectively. Company matching payments vest over 7 years.
 
   
13.  SUBSEQUENT EVENTS
    
 
STATUTORY MERGER AND CHANGE IN TAX STATUS
 
    On March 1, 1999, Juno Online Services, L.P. and Juno Online Services, Inc.,
entities under common control, effected a statutory merger pursuant to which
Juno Online Services, L.P. was merged with and into Juno Online Services, Inc.,
in a manner similar to a pooling of interests (the "Statutory Merger"). This tax
free transaction resulted in the combination of Juno Online Services, L.P. (the
"Partnership") with its wholly owned subsidiary, Juno Online Services, Inc. such
that Juno Online Services, Inc. is the surviving entity. In connection with the
Statutory Merger, the Class A Units of the Partnership were converted into
Series A Redeemable Convertible Preferred Stock (see below), and accumulated
losses of the Partnership were reclassified to additional paid-in capital.
 
    Prior to the Statutory Merger, U.S. federal and state income taxes have not
been provided because the partners reported their respective share of the
Company's losses on their respective returns. The Company has incurred
accumulated book losses of $92,200 through December 31, 1998. Accumulated tax
losses through to December 31, 1998 amounted to $81,101. Had the Company been
subject to corporate income taxes, it would have recorded a deferred tax asset
(estimated at an effective rate of 40%), subject to a full valuation allowance.
This pro forma net deferred tax asset (pro forma to exclude the effect of tax
losses which passed through to the former partners) is comprised of the
following:
 
<TABLE>
<S>                                                                   <C>
Deferred revenue....................................................  $   1,593
Start-up costs, capitalized for tax purposes........................      1,417
Accrued expenses and other..........................................      1,386
                                                                      ---------
                                                                          4,396
Valuation allowance.................................................     (4,396)
                                                                      ---------
                                                                      $      --
                                                                      ---------
                                                                      ---------
</TABLE>
 
    Deferred tax assets will be available to Juno Online Services, Inc. as the
successor company following the Statutory Merger.
 
ISSUANCE OF REDEEMABLE CONVERTIBLE PREFERRED STOCK
 
    In March 1999, the Company, after giving effect to the Statutory Merger,
received $61,800 in proceeds net of $3,200 of issuance costs, for the issuance
of 10,138,716 shares of Series B Redeemable Convertible Preferred Stock ("Series
B Preferred"), $.01 par value. In addition, 17,684,035 shares of Series A
Redeemable Convertible Preferred Stock ("Series A Preferred"), $.01 par value,
were issued to the holders of Series A Partnership Units in connection with the
Statutory Merger.
 
    Dividends are cumulative and payable at a rate of $0.64 per share per annum
with respect to the Series B Preferred and $0.41 per share per annum with
respect to the Series A Preferred. Dividends
 
                                      F-20
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
13.  SUBSEQUENT EVENTS (CONTINUED)
    
cease to accrue upon a public offering of common stock in which the aggregate
net proceeds to the Company are at least $40 million (a "Qualified Public
Offering").
 
    At any time on or after March 1, 2004, the holders of at least 66 2/3% of
the outstanding shares of Series B Preferred may require the Company to redeem
all shares of Series B Preferred. At any time after the holders of Series B
Preferred have demanded a redemption, the holders of a majority of the
outstanding shares of Series A Preferred may require the Company to redeem all
shares of Series A Preferred. The redemption price per share shall be $6.41 for
Series B Preferred and $4.50 for Series A Preferred (both as adjusted for any
stock dividends payable in shares of the respective series of Preferred Stock or
combinations or splits of Preferred Stock, plus any accrued but unpaid
dividends).
 
    The holders of Preferred Stock shall have the right, at their option, at any
time, to convert such shares of Preferred Stock into such number of fully paid
and non-assessable shares of Common Stock as is obtained by multiplying the
number of shares of Series B or Series A Preferred to be converted by the
fraction obtained by dividing the Original Series Issue Price ($6.41 for Series
B Preferred and $4.50 for Series A Preferred) by the Applicable Conversion Price
in effect on the date the certificate is surrendered for conversion ($6.41 for
Series B Preferred and $4.50 for Series A Preferred on date of issuance, subject
to future adjustment).
 
    In the event that, at any time while any of the Preferred Stock shall be
outstanding, the Company completes a Qualified Public Offering, then all
outstanding shares of Preferred Stock shall be converted into shares of Common
Stock in accordance with the conversion calculation above.
 
    If the Company for any reason (including the failure to have sufficient
funds available) fails to redeem on any redemption date the amount due to the
holders of Series B Preferred shall bear interest at the prime rate plus 6% per
annum, compounded annually. In addition, the holders of a majority of Series B
Preferred shall have the right, to the exclusion of the holders of Series A
Preferred or Common Stock, to elect a majority of the directors of the Company,
subject to certain conditions as specified in the Certificate of Incorporation.
 
    Upon any liquidation of the Company, the holders of the Series B Preferred
shall be entitled, before any distribution is made upon any Series A Preferred
or Common Stock, to be paid with respect to each outstanding share of Series B
Preferred an amount equal to $1.91 per share (the "Series B Liquidation
Preference"). After holders of Series B Preferred have been paid the Series B
Liquidation Preference, the holders of Series A Preferred and the holders of
Series B Preferred shall be entitled, before any distribution is made upon the
Common Stock, to be paid with respect to each outstanding share of their
respective series of Preferred Stock an amount equal to $4.50 per share.
 
    After the holders of Preferred Stock shall have been paid in full the
preferential amounts to which they are entitled as provided in the preceding
paragraph, the holders of Common Stock, together with the holders of Preferred
Stock, shall be entitled to share ratably according to the number of shares of
Common Stock held by them (or issuable to them upon conversion of shares of the
Preferred Stock).
 
   
    Holders of Preferred Stock shall have one vote for each full share of Common
Stock into which their respective series of Preferred Stock are convertible on
the record date for the vote.
    
 
                                      F-21
<PAGE>
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
         (IN THOUSANDS, EXCEPT LIMITED PARTNERSHIP UNIT AND SHARE DATA)
 
   
13.  SUBSEQUENT EVENTS (CONTINUED)
    
   
PRO FORMA INFORMATION (UNAUDITED)
    
 
   
    The pro forma balance sheet as of March 31, 1999 reflects the conversion of
10,138,716 shares of Series B Redeemable Convertible Preferred Stock and
17,684,035 shares of Series A Redeemable Convertible Preferred Stock to
27,822,751 shares of common stock.
    
 
1999 STOCK INCENTIVE PLAN (UNAUDITED)
 
    The 1999 Stock Incentive Plan (the "1999 Plan") is intended to serve as the
successor equity incentive program to the 1997 Plan. The 1999 Plan became
effective on March 26, 1999. Under the 1999 Plan, 5,768,611 shares have been
authorized subject to automatic increases in January of each year. On the
effective date, shares authorized for issuance under the 1997 Plan will be
incorporated into the 1999 Plan. No further option grants will be made under the
1997 Plan. Options outstanding under the 1997 Plan will be incorporated into the
1999 Plan.
 
    The 1999 Stock Incentive Plan will include four programs. The first provides
for the discretionary grant of options to purchase common shares to employees,
consultants, and members of the board of directors. The second will allow
individuals to purchase shares or receive them as a bonus tied to the
performance of services. The third will allow executive officers and other
highly compensated employees to apply a portion of their salary to the
acquisition of special below-market stock option grants. The fourth program will
automatically grant options at periodic intervals to eligible non-employee board
members.
 
EMPLOYEE STOCK PURCHASE PLAN (UNAUDITED)
 
    On April 19, 1999, the Board of Directors approved the 1999 Employee Stock
Purchase Plan (the "1999 ESPP"), subject to stockholder approval. A total of
555,556 shares are available to be issued under the 1999 ESPP. The 1999 ESPP
allows eligible employees to purchase shares of common stock at semi-annual
intervals, through periodic payroll deductions of up to 15% of cash earnings, as
defined. The purchase price per share is 85% of the lower of the fair market
value on the eligible employee's entry date or the fair market value on the
semi-annual purchase date. The 1999 ESPP will terminate no later than the last
business day in July 2009.
 
REVERSE STOCK SPLIT (UNAUDITED)
 
    On April 19, 1999, the Company's Board of Directors authorized a reverse
stock split. Accordingly, all share data and limited partnership units have been
restated for the retroactive effect of the reverse split as if it had occurred
at the beginning of the earliest period presented.
 
                                      F-22
<PAGE>
Back Cover:
 
[The Juno Member Profile]
 
The picture depicts each page of the electronic survey that Juno subscribers are
asked to complete. Each page contains questions relevant to its particular
topic. The upper left corner of the "General Account Information" page is
magnified to show certain information entered by a hypothetical Juno subscriber.
An arrow points from that close-up to the following text at the bottom of the
page:
 
"Detailed Information About Millions of Subscribers--All subscribers to Juno's
basic e-mail service are required to complete a detailed electronic survey
containing questions about age, gender, income, hobbies, interests, family size,
education, patters of computer use, expected purchases, and more. Advertisements
on our service may be targeted to a narrowly specified subset of our subscriber
base on the basis of any combination of Member Profile data."
 
                                                                     [Juno Logo]
<PAGE>
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                                6,500,000 SHARES
                           JUNO ONLINE SERVICES, INC.
                                  COMMON STOCK
 
                                        [LOGO]
 
                                    --------
 
                                   PROSPECTUS
 
                                           , 1999
 
                                    --------
 
                              SALOMON SMITH BARNEY
                            BEAR, STEARNS & CO. INC.
                            PAINEWEBBER INCORPORATED
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 13. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION
 
    The following table sets forth the estimated costs and expenses, other than
the underwriting discounts and commissions, payable by the registrant in
connection with the sale of the common stock being registered.
 
<TABLE>
<CAPTION>
                                                                                                       AMOUNT TO
                                                                                                        BE PAID
                                                                                                      ------------
<S>                                                                                                   <C>
SEC registration fee................................................................................  $     27,015
NASD filing fee.....................................................................................        10,218
Nasdaq National Market listing fee..................................................................        95,000
Legal fees and expenses.............................................................................       350,000
Accounting fees and expenses........................................................................       175,000
Printing and engraving..............................................................................       250,000
Transfer agent fees.................................................................................        10,000
Miscellaneous.......................................................................................        82,767
                                                                                                      ------------
    Total...........................................................................................  $  1,000,000
                                                                                                      ------------
                                                                                                      ------------
</TABLE>
 
ITEM 14. INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
   
    The registrant's Amended and Restated Certificate of Incorporation in effect
as of the date hereof, and the registrant's Amended and Restated Certificate of
Incorporation to be in effect upon the closing of this offering (collectively,
the "Certificate") provides that the liability of a director of the registrant
shall be eliminated or limited to the fullest extent permitted by the Delaware
General Corporation Law, as amended (the "DGCL"). Under the DGCL, the directors
have a fiduciary duty to the registrant which is not eliminated by this
provision of the Certificate and, in appropriate circumstances, equitable
remedies such as injunctive or other forms of non-monetary relief will remain
available. In addition, each director will continue to be subject to liability
under the DGCL for breach of the director's duty of loyalty to the registrant,
for acts or omissions which are found by a court of competent jurisdiction to be
not in good faith or involving intentional misconduct, for knowing violations of
law, for actions leading to improper personal benefit to the director, and for
payment of dividends or approval of stock repurchases or redemptions that are
prohibited by DGCL. This provision also does not affect the directors'
responsibilities under any other laws, such as the Federal securities laws or
state or Federal environmental laws. The registrant intends to obtain liability
insurance for its officers and directors.
    
 
    Section 145 of the DGCL empowers a corporation to indemnify its directors
and officers and to purchase insurance with respect to liability arising out of
their capacity or status as directors and officers, provided that this provision
shall not eliminate or limit the liability of a director: (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) arising under Section 174 of the DGCL, or (iv)
for any transaction from which the director derived an improper personal
benefit. The DGCL provides further that the indemnification permitted thereunder
shall not be deemed exclusive of any other rights to which the directors and
officers may be entitled under the corporation's bylaws, any agreement, a vote
of stockholders or otherwise. The Certificate eliminates the personal liability
of directors to the fullest extent permitted by Section 102(b)(7) of the DGCL
and provides that the registrant shall fully indemnify any person who was or is
a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding whether civil, criminal, administrative or
investigative, by reason of the fact that such person is or was a director or
officer of the registrant, or is or was serving at the request of the registrant
as a director or
 
                                      II-1
<PAGE>
officer of another corporation, partnership, joint venture, trust, employee
benefit plan or other enterprise, against expenses (including attorney's fees),
judgments, fines and amounts paid in settlement actually and reasonably incurred
by such person in connection with such action, suit or proceeding.
 
    At present, there is no pending litigation or proceeding involving any
director, officer, employee or agent as to which indemnification will be
required or permitted under the Certificate. The registrant is not aware of any
threatened litigation or proceeding that may result in a claim for this type of
indemnification.
 
ITEM 15. RECENT SALES OF UNREGISTERED SECURITIES
 
    The registrant has sold and issued the following securities since June 30,
1995 (inception):
 
    PARTNERSHIP UNITS.  Between June 30, 1995 and March 1, 1999, the registrant
issued a total of 17,684,035 limited partnership units for a price per unit of
$4.50. These units were all purchased by entities or persons affiliated with D.
E. Shaw & Co., Inc. Of the 17,684,035 units issued, 872,192 were issued in 1995,
4,646,098 were issued in 1996, 10,276,854 were issued in 1997 and 1,888,891 were
issued in 1998. On March 1, 1999, Juno Online Services, L.P. was merged with and
into Juno Online Services, Inc., its wholly owned subsidiary. In connection with
this merger, each outstanding partnership unit was converted into one share of
Series A Redeemable Convertible Preferred Stock. Upon the closing of this
offering, the shares of Series A Redeemable Convertible Preferred Stock will
automatically convert into shares of the registrant's common stock.
 
    PREFERRED STOCK.  On March 1, 1999 and March 4, 1999, the registrant issued
a total of 10,138,716 shares of Series B Redeemable Convertible Preferred Stock
to a group of investors including affiliates of Intel Corporation, News
Corporation, Prospect Street Ventures and Sycamore Ventures. PaineWebber
Incorporated acted as the placement agent in connection with the sale of this
Series B Redeemable Convertible Preferred Stock. Upon the closing of this
offering, the shares of Series B Redeemable Convertible Preferred Stock will
automatically convert into shares of the registrant's common stock.
 
    OPTIONS.  The registrant has from time to time granted options to purchase
shares of common stock to employees in reliance upon exemptions from
registration pursuant to either (i) Section 4(2) of the Securities Act of 1933,
as amended, or (ii) Rule 701 promulgated under the Securities Act of 1933, as
amended. The following table sets forth information regarding these grants and
assumes a 1 for 4.5 reverse stock split of the registrant's common stock to be
effected prior to the closing of this offering.
 
   
<TABLE>
<CAPTION>
                                                                                      WEIGHTED
                                                                                       AVERAGE
                                                                         NUMBER OF    EXERCISE
                                                                           SHARES       PRICE
                                                                         ----------  -----------
<S>                                                                      <C>         <C>
June 30, 1995 (inception) to December 31, 1996.........................      --          --
January 1, 1997 to December 31, 1997...................................   1,495,546   $    0.45
January 1, 1998 to December 31, 1998...................................   1,577,437   $    0.84
January 1, 1999 to May 5, 1999.........................................   1,034,841   $   12.00
</TABLE>
    
 
    The above securities were offered and sold by the registrant in reliance
upon exemptions from registration pursuant to either (i) Section 4(2) of the
Securities Act of 1933, as amended, as transactions not involving any public
offering, or (ii) Rule 701 promulgated under the Securities Act of 1933, as
amended. No underwriters were involved in connection with the sales of
securities referred to in this Item 15, except for PaineWebber Incorporated,
which acted as the placement agent in connection with the sale of Series B
Redeemable Convertible Preferred Stock in March 1999.
 
                                      II-2
<PAGE>
ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
 
    (a) Exhibits.
 
   
<TABLE>
<CAPTION>
NUMBER                                                    DESCRIPTION
- ------------  ----------------------------------------------------------------------------------------------------
<C>           <S>
   1.1*       Form of Underwriting Agreement.
   3.1**      Certificate of Incorporation.
   3.2**      Certificate of Amendment to Certificate of Incorporation, filed March 1, 1999.
   3.3**      Certificate of Amendment to Certificate of Incorporation, filed March 1, 1999.
   3.4**      Certificate of Amendment to Certificate of Incorporation, filed March 4, 1999.
   3.5        Form of Amended and Restated Certificate of Incorporation to be in effect upon the closing of this
              offering.
   3.6**      Bylaws.
   3.7        Form of Amended and Restated Bylaws to be in effect upon the closing of this offering.
   4.1**      Specimen Common Stock certificate.
   4.2**      See Exhibits 3.1, 3.2, 3.3, 3.4, 3.5 and 3.6 for provisions defining the rights of holders of common
              stock of the registrant.
   5.1        Opinion of Brobeck, Phleger & Harrison LLP.
  10.1**      1999 Stock Incentive Plan.
  10.2**      1999 Employee Stock Purchase Plan.
  10.3**      Amended and Restated Registration Rights Agreement.
  10.4**+     Marketing Services Agreement, dated September 30, 1998, among the registrant and Hartford Fire
              Insurance Company and its affiliates/subsidiaries.
  10.5**+     Marketing Services Agreement, dated December 11, 1998, between the registrant and AT&T Wireless
              Services, Inc.
  10.6**+     Distributor Agreement, dated March 12, 1998, between the registrant and LCI International Telecom
              Corp.
  10.7**+     Financial Services Marketing Agreement, dated February 17, 1999, between the registrant and First
              USA Bank, N.A.
  10.8**+     Master Service Agreement, dated August 1, 1998, between the registrant and Softbank Services Group.
  10.9**      India Services Agreement, dated November 1, 1997, between the registrant and D. E. Shaw & Co., L.P.
  10.10**     Services Agreement, dated January 1, 1998, between the registrant and D. E. Shaw & Co., L.P.
  10.11**     Advertising Agreement, dated March 1, 1999, between the registrant and News America Incorporated.
  10.12(a)**  Employment Agreement, dated September 2, 1998, between the registrant and Charles Ardai.
  10.12(b)    Employment Agreement, dated April 26, 1999, between the registrant and Charles Ardai.
  10.13(a)**  Employment Agreement, dated June 10, 1998, between the registrant and Robert Cherins.
  10.13(b)    Employment Agreement, dated April 26, 1999, between the registrant and Robert Cherins.
  10.14**     Employment Agreement, dated April 6, 1998, between the registrant and Mark Moraes.
  10.15**     Employment Agreement, dated September 25, 1998, between the registrant and Richard Eaton.
  23.1        Consent of Brobeck, Phleger & Harrison LLP (included in Exhibit 5.1).
  23.2        Consent of PricewaterhouseCoopers LLP.
</TABLE>
    
 
                                      II-3
<PAGE>
   
<TABLE>
<CAPTION>
NUMBER                                                    DESCRIPTION
- ------------  ----------------------------------------------------------------------------------------------------
<C>           <S>
  24.1**      Powers of Attorney.
  27.1**      Financial Data Schedule for the twelve months ended December 31, 1998.
  27.2**      Financial Data Schedule for the three months ended March 31, 1999.
</TABLE>
    
 
- ------------------------
 
*   To be supplied by amendment.
 
   
**  Previously filed.
    
 
+   Confidential treatment requested for portions of this agreement.
 
    (b) Financial Statement Schedule.
 
            SCHEDULE II -- Valuation and Qualifying Accounts
 
ITEM 17. UNDERTAKINGS
 
    The undersigned registrant hereby undertakes to provide to the Underwriter
at the closing specified in the Underwriting Agreement, certificates in such
denominations and registered in such names as required by the Underwriter to
permit prompt delivery to each purchaser.
 
    Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Act, and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of counsel the matter has
been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.
 
    The undersigned registrant hereby undertakes that:
 
    (1) For purposes of determining any liability under the Securities Act of
1933, the information omitted from the form of prospectus filed as part of this
registration statement in reliance upon Rule 430A and contained in a form of
prospectus filed by the registrant pursuant to Rule 424 (b)(1) or (4), or 497(h)
under the Securities Act of 1933, shall be deemed to be part of this
registration statement as of the time it was declared effective.
 
    (2) For the purpose of determining any liability under the Securities Act of
1933, each post-effective amendment that contains a form of prospectus shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial BONA FIDE offering thereof.
 
                                      II-4
<PAGE>
                                   SIGNATURES
 
   
    Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant has duly caused this Amendment No. 2 to the registration statement to
be signed on its behalf by the undersigned, thereunto duly authorized in The
City of New York, State of New York, on this 7th day of May, 1999.
    
 
                                JUNO ONLINE SERVICES, INC.
 
                                By:  /s/ CHARLES E. ARDAI
                                     -----------------------------------------
                                     Name: Charles E. Ardai
                                     Title:  President
 
   
    Pursuant to the requirements of the Securities Act of 1933, as amended, this
Amendment No. 2 to the Registration Statement has been signed by the following
persons in the capacities indicated on May 7, 1999.
    
 
          SIGNATURE             TITLE(S)
- ------------------------------  ---------------------------
 
     /s/ CHARLES E. ARDAI       President and Director
- ------------------------------    (principal executive
       Charles E. Ardai           officer)
 
                                Chief Financial Officer and
  /s/ RICHARD M. EATON, JR.       Treasurer (principal
- ------------------------------    accounting and financial
    Richard M. Eaton, Jr.         officer)
 
              *                 Director
- ------------------------------
       Edward J. Ryeom
 
              *                 Director
- ------------------------------
       Louis K. Salkind
 
              *                 Director
- ------------------------------
        David E. Shaw
 
<TABLE>
<S>   <C>                        <C>                         <C>
*By:    /s/ CHARLES E. ARDAI
      -------------------------
          Charles E. Ardai
          ATTORNEY-IN-FACT
</TABLE>
 
                                      II-5
<PAGE>
                               INDEX TO EXHIBITS
 
   
<TABLE>
<CAPTION>
 NUMBER                                                   DESCRIPTION
- -----------  -----------------------------------------------------------------------------------------------------
<C>          <S>
      1.1*   Form of Underwriting Agreement.
      3.1**  Certificate of Incorporation.
      3.2**  Certificate of Amendment to Certificate of Incorporation, filed March 1, 1999.
      3.3**  Certificate of Amendment to Certificate of Incorporation, filed March 1, 1999.
      3.4**  Certificate of Amendment to Certificate of Incorporation, filed March 4, 1999.
      3.5    Form of Amended and Restated Certificate of Incorporation to be in effect upon the closing of this
             offering.
      3.6**  Bylaws.
      3.7    Form of Amended and Restated Bylaws to be in effect upon the closing of this offering.
      4.1**  Specimen Common Stock certificate.
      4.2**  See Exhibits 3.1, 3.2, 3.3, 3.4, 3.5 and 3.6 for provisions defining the rights of holders of common
             stock of the registrant.
      5.1    Opinion of Brobeck, Phleger & Harrison LLP.
     10.1**  1999 Stock Incentive Plan.
     10.2**  1999 Employee Stock Purchase Plan.
     10.3**  Amended and Restated Registration Rights Agreement.
    10.4**+  Marketing Services Agreement, dated September 30, 1998, among the registrant and Hartford Fire
             Insurance Company and its affiliates/subsidiaries.
    10.5**+  Marketing Services Agreement, dated December 11, 1998, between the registrant and AT&T Wireless
             Services, Inc.
    10.6**+  Distributor Agreement, dated March 12, 1998, between the registrant and LCI International Telecom
             Corp.
    10.7**+  Financial Services Marketing Agreement, dated February 17, 1999, between the registrant and First USA
             Bank, N.A.
    10.8**+  Master Service Agreement, dated August 1, 1998, between the registrant and Softbank Services Group.
     10.9**  India Services Agreement, dated November 1, 1997, between the registrant and D. E. Shaw & Co., L.P.
    10.10**  Services Agreement, dated January 1, 1998, between the registrant and D. E. Shaw & Co., L.P.
    10.11**  Advertising Agreement, dated March 1, 1999, between the registrant and News America Incorporated.
     10.12(a)** Employment Agreement, dated September 2, 1998, between the registrant and Charles Ardai.
     10.12(b) Employment Agreement, dated April 26, 1999, between the registrant and Charles Ardai.
     10.13(a)** Employment Agreement, dated June 10, 1998, between the registrant and Robert Cherins.
     10.13(b) Employment Agreement, dated April 26, 1999, between the registrant and Robert Cherins.
    10.14**  Employment Agreement, dated April 16, 1998, between the registrant and Mark Moraes.
    10.15**  Employment Agreement, dated September 25, 1998, between the registrant and Richard Eaton.
     23.1    Consent of Brobeck, Phleger & Harrison LLP (included in Exhibit 5.1).
     23.2    Consent of PricewaterhouseCoopers LLP.
     24.1**  Powers of Attorney (See Signature Page).
     27.1**  Financial Data Schedule for the twelve months ended December 31, 1998.
     27.2**  Financial Data Schedule for the three months ended March 31, 1999.
</TABLE>
    
 
- ------------------------
 
*   To be supplied by amendment.
 
   
**  Previously filed.
    
 
+   Confidential treatment requested for portions of this agreement.
<PAGE>
                       REPORT OF INDEPENDENT ACCOUNTANTS
 
To the Board of Directors and Stockholders of
Juno Online Services, Inc.:
 
    In connection with our audits of the consolidated financial statements of
Juno Online Services, Inc. (formerly Juno Online Services, L.P. & Subsidiary) as
of December 31, 1997 and 1998, and for each of the three years in the period
ended December 31, 1998, which financial statements are included in the
registration statement on Form S-1, we have also audited the financial statement
schedule listed in Item 16(b) herein.
 
    In our opinion, the financial statement schedule, when considered in
relation to the basic financial statements taken as a whole, presents fairly, in
all material respects, the information required to be included therein.
 
/s/ PricewaterhouseCoopers LLP
 
New York, New York
March 4, 1999
 
                                      S-1
<PAGE>
                 SCHEDULE II- VALUATION AND QUALIFYING ACCOUNTS
 
                           JUNO ONLINE SERVICES, INC.
               (FORMERLY JUNO ONLINE SERVICES, L.P. & SUBSIDIARY)
 
<TABLE>
<CAPTION>
                                                                    BALANCE AT     ADDITIONS
                                                                   BEGINNING OF    COSTS AND                   BALANCE AT
CLASSIFICATION                                                        PERIOD       EXPENSES    DEDUCTIONS(A)  END OF PERIOD
- -----------------------------------------------------------------  -------------  -----------  -------------  -------------
<S>                                                                <C>            <C>          <C>            <C>
  Year ended December 31, 1996:
    Allowance for doubtful accounts..............................    $       0     $       9     $       0      $       9
  Year ended December 31, 1997:
    Allowance for doubtful accounts..............................    $       9     $     233     $    (136)     $     106
  Year ended December 31, 1998:
    Allowance for doubtful accounts..............................    $     106     $     377     $    (187)     $     296
</TABLE>
 
- ------------------------
 
(a) Represents sales concessions and accounts written-off as uncollectible.
 
                                      S-2



<PAGE>
                                                                     Exhibit 3.5


                AMENDED AND RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                           JUNO ONLINE SERVICES, INC.


                  (Pursuant to Sections 228, 242 and 245 of the
                General Corporation Law of the State of Delaware)


                  Juno Online Services, Inc. (the "Corporation"), a corporation
organized and existing under the General Corporation Law of the State of
Delaware (the "GCL"),

                  DOES HEREBY CERTIFY:

                  FIRST: That the Corporation was originally incorporated in
Delaware, and the date of its filing of its original Certificate of
Incorporation with the Secretary of State of Delaware was July 2, 1996. On March
1, 1999, the Corporation filed with the Secretary of State of the State of
Delaware two Certificates of Amendment to its Certificate of Incorporation. On
March 1, 1999, the Corporation filed with the Secretary of State of the State of
Delaware a Certificate of Agreement of Merger which merged Juno Online Services,
L.P., a Delaware limited partnership, with and into the Corporation. On March 4,
1999, the Corporation filed a Certificate of Amendment to its Certificate of
Incorporation.

                  SECOND: That the Board of Directors duly adopted resolutions
proposing to amend and restate the Certificate of Incorporation, as amended, of
the Corporation, and that thereafter, pursuant to such resolutions of the Board
of Directors, a consent of stockholders in lieu of meeting was signed by the
holders of outstanding stock having not less than the minimum number of votes
that would be necessary to authorize or take such action at a meeting at which
all shares entitled to vote thereon would have been present and voted.

                  THIRD: That said amendment was duly adopted in accordance with
the provisions of Sections 228, 242 and 245 of the GCL.

                  FOURTH: The Certificate of Incorporation, as amended, of the
Corporation shall be amended and restated in its entirety as follows:

                                   ARTICLE I

                  The name of the Corporation is Juno Online Services, Inc.

                                   ARTICLE II

                  The address of the Corporation's registered office in the
State of Delaware is 1013 Centre Road, Wilmington, Delaware 19805. The name of
its registered agent at such address is Corporation Service Company, New Castle
County.


<PAGE>

                                  ARTICLE III

                  The nature of the business or purposes to be conducted or
promoted is to engage in any lawful business or purposes for which a corporation
may be organized under the GCL.

                                  ARTICLE IV

         A. CLASSES OF STOCK. The Corporation is authorized to issue two classes
of stock to be designated, respectively, "Common Stock" and "Preferred Stock."
The total number of shares which the Corporation is authorized to issue is Six
Hundred Five Million (605,000,000) shares. Six Hundred Million (600,000,000)
shares, par value $0.01 per share, shall be Common Stock and Five Million
(5,000,000) shares, par value $0.01 per share, shall be Preferred Stock.

         B. COMMON STOCK.

                  (1) GENERAL. All shares of Common Stock will be identical and
will entitle the holders thereof to the same rights, powers and privileges. The
rights, powers and privileges of the holders of the Common Stock are subject to
and qualified by the rights of holders of any then outstanding Preferred Stock.

                  (2) DIVIDENDS. Dividends may be declared and paid on the
Common Stock from funds lawfully available therefor as and when determined by
the Board of Directors and subject to any preferential dividend rights of any
then outstanding Preferred Stock.

                  (3) DISSOLUTION, LIQUIDATION OR WINDING UP. In the event of
any dissolution, liquidation or winding up of the affairs of the Corporation,
whether voluntary or involuntary, each issued and outstanding share of Common
Stock shall entitle the holder thereof to receive an equal portion of the net
assets of the Corporation available for distribution to the holders of Common
Stock after the payment of all debts and other liabilities and subject to any
preferential rights of any then outstanding Preferred Stock.

                  (4) VOTING RIGHTS. Except as otherwise required by law or this
Amended and Restated Certificate of Incorporation, each holder of Common Stock
shall have one vote in respect of each share of stock held of record by such
holder on the books of the Corporation for the election of directors and on all
matters submitted to a vote of stockholders of the Corporation. Except as
otherwise required by law or provided herein, holders of Preferred Stock shall
vote together with holders of Common Stock as a single class, subject to any
special or preferential voting rights of any then outstanding Preferred Stock.
There shall be no cumulative voting.

                  (5) REDEMPTION. The Common Stock is not redeemable.

         C. PREFERRED STOCK. The Board of Directors is authorized, subject to
limitations prescribed by law, by the rules of a national securities exchange,
if applicable, and by the provisions of this ARTICLE IV, to provide for the
issuance of up to an aggregate of Five Million (5,000,000) shares of Preferred
Stock in one or more series, and by filing a certificate pursuant to the
applicable law of the State of Delaware, to establish from time to time the
number of shares



                                       2
<PAGE>

to be included in each such series, and to fix the designation, powers,
preferences, and rights of the shares of each such series and the
qualifications, limitations or restrictions thereof.

                  The authority of the Board of Directors with respect to each
series shall include, but not be limited to, determination of the following:

                  (1) The number of shares constituting that series and the
distinctive designation of that series;

                  (2) The dividend rate on the shares of that series, whether
dividends shall be cumulative, and, if so, from which date or dates, and the
relative rights of priority, if any, of payment of dividends on shares of that
series;

                  (3) Whether that series shall have voting rights, in addition
to the voting rights provided by law, and, if so, the terms of such voting
rights;

                  (4) Whether that series shall have conversion privileges, and,
if so, the terms and conditions of such conversion, including provision for
adjustment of the conversion rate in such events as the Board of Directors shall
determine;

                  (5) Whether or not the shares of that series shall be
redeemable, and, if so, the terms and conditions of such redemption, including
the date or dates upon or after which they shall be redeemable, and the amount
per share payable in case of redemption, which amount may vary under different
conditions and at different redemption dates;

                  (6) Whether that series shall have a sinking fund for the
redemption or purchase of shares of that series, and, if so, the terms and
amount of such sinking fund;

                  (7) The rights of the shares of that series in the event of
voluntary or involuntary liquidation, dissolution or winding up of the
Corporation, and the relative rights or priority, if any, of payment of shares
of that series; and

                  (8) Any other relative rights, preferences and limitations of
that series.

                  Dividends on outstanding shares of Preferred Stock shall be
paid or declared and set apart for payment before any dividends shall be paid or
declared and set apart for payment on the Common Stock with respect to the same
dividend period.

                  If upon any voluntary or involuntary liquidation, dissolution
or winding up of the Corporation, the assets available for distribution to
holders of shares of Preferred Stock of all series shall be insufficient to pay
such holders the full preferential amount to which they are entitled, then such
assets shall be distributed ratably among the shares of all series of Preferred
Stock in accordance with the respective preferential amounts (including unpaid
cumulative dividends, if any) payable with respect thereto.

         D. PREEMPTIVE RIGHTS. No holder of any of the shares of any class or
series of stock or of options, warrants or other rights to purchase shares of
any class or series of stock or of other securities of the Corporation shall
have any preemptive right to purchase or subscribe for 



                                       3
<PAGE>

any unissued stock of any class or series, or any unissued bonds, certificates
of indebtedness, debentures or other securities convertible into or exchangeable
for stock of any class or series or carrying any right to purchase stock of any
class or series; but any such unissued stock, bonds, certificates or
indebtedness, debentures or other securities convertible into or exchangeable
for stock or carrying any right to purchase stock may be issued pursuant to
resolution of the Board of Directors to such persons, firms, corporations or
associations, whether or not holders thereof, and upon such terms as may be
deemed advisable by the Board of Directors in the exercise of its sole
discretion.

                                   ARTICLE V

         A. NUMBER. The number of directors of the Corporation shall be fixed
from time to time by, or in the manner provided in the Bylaws or by resolution
duly adopted by the Board of Directors, provided that no action shall be taken
to decrease or increase the number of directors unless at least 66.67% of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors (considered for this purpose as one
class) cast at a meeting of the stockholders called for that purpose approve
such decrease or increase. Vacancies occurring in the Board of Directors for any
reason and newly created directorships shall be filled by a vote of a majority
of the remaining members of the Board of Directors, even if less than a quorum,
at any meeting of the Board of Directors. A director so chosen shall hold office
for the remainder of the full term of the director for which the vacancy was
created or occurred and until such director's successor shall have been duly
elected and qualified.

         B. CLASSIFIED BOARD OF DIRECTORS. The directors of the Corporation
shall be divided into three (3) classes as nearly equal in size as is
practicable, hereby designated Class I, Class II and Class III. For the purposes
hereof, the initial Class I, Class II and Class III directors shall be those
directors so designated by a resolution of the Board of Directors. At the first
annual meeting of stockholders following the closing of the initial public
offering of the Corporation's Common Stock, the term of office of the Class I
directors shall expire and Class I directors shall be elected for a full term of
three (3) years. At the second annual meeting of stockholders following the
closing of the initial public offering of the Corporation's Common Stock, the
term of office of the Class II directors shall expire and Class II directors
shall be elected for a full term of three (3) years. At the third annual meeting
of stockholders following the initial public offering of the Corporation's
Common Stock, the term of office of the Class III directors shall expire and
Class III directors shall be elected for a full term of three (3) years. At each
succeeding annual meeting of stockholders, directors shall be elected for a full
term of three (3) years to succeed the directors of the class whose terms expire
at such annual meeting. If the number of directors is hereafter changed, each
director then serving as such shall nevertheless continue as a director of the
Class of which he is a member until the expiration of his current term and any
newly created directorships or decrease in directorships shall be so apportioned
among the classes as to make all classes as nearly equal in number as is
practicable.

                  In the event of any increase or decrease in the authorized
number of directors, (1) each director then serving as such shall nevertheless
continue as a director of the class of which he is a member until the expiration
of his current term, or his earlier resignation, removal from office or death,
and (2) the newly created or eliminated directorship resulting from such

                                       4
<PAGE>

increase or decrease shall be appointed by the Board of Directors among the
three classes of directors so as to maintain such classes as nearly equal as
possible.

         C. REMOVAL OF DIRECTORS. Notwithstanding any other provisions of this
Amended and Restated Certificate of Incorporation or the Bylaws of the
Corporation, any director or the entire Board of Directors may be removed, at
any time, but only for cause and only by the affirmative vote of the holders of
not less than 66.67% of the outstanding shares of capital stock of the
Corporation entitled to vote generally in the election of directors (considered
for this purpose as one class) cast at a meeting of the stockholders called for
that purpose. Notwithstanding the foregoing, whenever the holders of any one or
more series of preferred stock of the Corporation shall have the right, voting
separately as a class, to elect one or more directors of the Corporation, the
preceding provisions of this ARTICLE V shall not apply with respect to the
director or directors elected by such holders of preferred stock.

                                   ARTICLE VI

                  Stockholders of the Corporation shall take action by meetings
held pursuant to this Amended and Restated Certificate of Incorporation and the
Bylaws and shall have no right to take any action by written consent without a
meeting. Meetings of stockholders may be held within or without the State of
Delaware, as the Bylaws may provide. The books of the Corporation may be kept
(subject to any provision contained in the statutes) outside the State of
Delaware at such place or places as may be designated from time to time by the
Board of Directors or in the Bylaws.

                                  ARTICLE VII

                  The liability of a director of the Corporation shall be 
eliminated or limited to the fullest extent permitted by the GCL. If the GCL 
is amended after approval by the stockholders of this ARTICLE VII to 
authorize corporate action further eliminating or limiting the personal 
liability of directors, then the liability of a director of the Corporation 
shall be eliminated or limited to the fullest extent permitted by the GCL, as 
so amended. No amendment to or repeal of this provision shall apply to or 
have any effect on the liability or alleged liability of any director of the 
Corporation for or with respect to any acts or omissions of such director 
occurring prior to such amendment.

                                  ARTICLE VIII

                  To the fullest extent permitted by applicable law, this
Corporation is authorized to provide indemnification of (and advancement of
expenses to) directors, officers, employees and agents (and any other persons to
which Delaware law permits this Corporation to provide indemnification) through
Bylaw provisions, agreements with such agents or other persons, vote of
stockholders or disinterested directors or otherwise, in excess of the
indemnification and advancement otherwise permitted by Section 145 of the GCL
subject only to limits created by applicable Delaware law (statutory or
non-statutory), with respect to action for breach of duty to the Corporation,
its stockholders, and others.

                                       5
<PAGE>

                  No director of the Corporation shall be personally liable to
the Corporation or any stockholder for monetary damages for breach of fiduciary
duty as a director, except for any matter in respect of which such director
shall be liable under Section 174 of the GCL or any amendment thereto or shall
be liable by reason that, in addition to any and all other requirements for such
liability, such director (1) shall have breached the director's duty or loyalty
to the Corporation or its stockholders, (2) shall have acted in manner involving
intentional misconduct or a knowing violation of law or, in failing to act,
shall have acted in a manner involving intentional misconduct or a knowing
violation of law, or (3) shall have derived an improper personal benefit. If the
GCL is hereafter amended to authorize the further elimination or limitation of
the liability of a director, the liability of a director of the Corporation
shall be eliminated or limited to the fullest extent permitted by the GCL, as so
amended.

                  Each person who was or is made a party or is threatened to be
made a party to or is in any way involved in any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (hereinafter a "proceeding"), including any appeal therefrom, by
reason of the fact that he or she, or a person of whom he or she is the legal
representative, is or was a director or officer of the Corporation or a direct
or indirect subsidiary of the Corporation, or is or was serving at the request
of the Corporation as a director or officer of another entity or enterprise, or
was a director or officer of a foreign or domestic corporation which was a
predecessor corporation of the Corporation or of another entity or enterprise at
the request of such predecessor corporation, shall be indemnified and held
harmless by the Corporation, and the Corporation shall advance all expenses
incurred by any such person in defense of any such proceeding prior to its final
determination, to the fullest extent authorized by the GCL. In any proceeding
against the Corporation to enforce these rights, such person shall be presumed
to be entitled to indemnification and the Corporation shall have the burden of
proving that such person has not met the standards of conduct for permissible
indemnification set forth in the GCL. The rights to indemnification and
advancement of expenses conferred by this Article VIII shall be presumed to have
been relied upon by the directors and officers of the Corporation in serving or
continuing to serve the Corporation and shall be enforceable as contract rights.
Said rights shall not be exclusive of any other rights to which those seeking
indemnification may otherwise be entitled. The Corporation may, upon written
demand presented by a director or officer of the Corporation or of a direct or
indirect subsidiary of the Corporation, or by a person serving at the request of
the Corporation as a director or officer of another entity or enterprise, enter
into contracts to provide such persons with specified rights to indemnification,
which contracts may confer rights and protections to the maximum extent
permitted by the GCL, as amended and in effect from time to time.

                  If a claim under this Article VIII is not paid in full by the
Corporation within sixty (60) days after a written claim has been received by
the Corporation, the claimant may at any time thereafter bring suit against the
Corporation to recover the unpaid amount of the claim and, if successful in
whole or in part, the claimant shall be entitled to be paid also the expenses of
prosecuting such claim. It shall be a defense to any such action (other than an
action brought to enforce the right to be advanced expenses incurred in
defending any proceeding prior to its final disposition where the required
undertaking, if any, has been tendered to the Corporation ) that the claimant
has not met the standards of conduct which make it permissible under the GCL for
the Corporation to indemnify the claimant for the amount claimed, but the
claimant shall be presumed to be entitled to indemnification and the Corporation
shall have the burden of proving 



                                       6
<PAGE>

that the claimant has not met the standards of conduct for permissible
indemnification set forth in the GCL.

                  If the GCL is hereafter amended to permit the Corporation to
provide broader indemnification rights that said Law permitted the Corporation
to provide prior to such amendment, the indemnification rights conferred by this
Article VIII shall be broadened to the fullest extent permitted by the GCL, as
so amended.

                                   ARTICLE IX

                  In furtherance of and not in limitation of powers conferred by
statute, the Board of Directors of the Corporation is expressly authorized to
adopt, repeal, alter, amend and rescind any or all of the Bylaws of the
Corporation.

                                   ARTICLE X

                  The Corporation reserves the right to repeal, alter, amend or
rescind any provision contained in this Amended and Restated Certificate of
Incorporation in the manner now or hereafter prescribed by law, and all rights
conferred on stockholders herein are granted subject to this reservation.
Notwithstanding the foregoing, the provisions set forth in ARTICLES V, VI, VII,
VIII, IX and this ARTICLE X may not be repealed, altered, amended or rescinded
in any respect without the affirmative vote of holders at least 66.67% of the
outstanding voting stock of the Corporation entitled to vote at election of
directors.

                                    * * *

                  FIFTH: That the foregoing amendment and restatement has been
duly adopted by the Board of Directors in accordance with the applicable
provisions of Section 242 and 245 of the GCL.

                  SIXTH: That the foregoing amendment and restatement was
approved by the holders of the requisite number of shares of the Corporation in
accordance with Section 228 of the GCL.


                                       7
<PAGE>


                  IN WITNESS WHEREOF, the undersigned have executed this
certificate on May __, 1999.


                                           Juno Online Services, Inc.



                                           By:                    
                                              --------------------------
                                              Charles E. Ardai
                                              President

Attest:


By:
   -------------------------- 
   Richard Buchband, Secretary


<PAGE>

                                                                     Exhibit 3.7



                           AMENDED AND RESTATED BYLAWS
                                       OF
                           JUNO ONLINE SERVICES, INC.









<PAGE>



                                                               TABLE OF CONTENTS
<TABLE>
<CAPTION>

                                                                                                               Page
                                                                                                               ----
<S>                                                                                                              <C>
ARTICLE I - OFFICES...............................................................................................1

         1.1      Registered Office...............................................................................1
         1.2      Other Offices...................................................................................1

ARTICLE II - MEETINGS OF STOCKHOLDERS.............................................................................1

         2.1      Place of Meetings...............................................................................1
         2.2      Annual Meeting..................................................................................1
         2.3      Special Meeting.................................................................................2
         2.4      Notice of Stockholder's Meeting.................................................................2
         2.5      Fixing Record Date for Stockholder Notice.......................................................2
         2.6      List of Stockholders Entitled to Vote...........................................................2
         2.7      Adjournments; Notice............................................................................2
         2.8      Waiver of Notice................................................................................3
         2.9      Quorum..........................................................................................3
         2.10     Voting and Proxies..............................................................................3
         2.11     Action at Meeting...............................................................................3
         2.12     General.........................................................................................3

ARTICLE III - DIRECTORS...........................................................................................4

         3.1      General Powers..................................................................................4
         3.2      Number; Election and Qualification..............................................................4
         3.3      Enlargement or Reduction of the Board...........................................................4
         3.4      Tenure..........................................................................................4
         3.5      Vacancies.......................................................................................4
         3.6      Resignation.....................................................................................5
         3.7      Regular Meetings................................................................................5
         3.8      Special Meetings................................................................................5
         3.9      Notice of Special Meetings......................................................................5
         3.10     Waiver of Notice................................................................................5
         3.11     Meetings by Telephone Conference Calls..........................................................5
         3.12     Quorum..........................................................................................5
         3.13     Adjourned Meeting...............................................................................6
         3.14     Action at Meeting...............................................................................6
         3.15     Action by Consent...............................................................................6
         3.16     Fees and Compensation of Directors..............................................................6
         3.17     Approval of Loans to Officers...................................................................6
         3.18     Removal.........................................................................................6
</TABLE>

<PAGE>

<TABLE>
<S>                                                                                                              <C>
ARTICLE IV - COMMITTEES...........................................................................................6

         4.1      Enumeration of Committees.......................................................................6
         4.2      Committee Minutes...............................................................................7
         4.3      Meetings and Action of Committees...............................................................7

ARTICLE V - OFFICERS..............................................................................................7

         5.1      Enumeration of Officers.........................................................................7
         5.2      Election of Officers............................................................................7
         5.3      Qualification and Tenure........................................................................7
         5.4      Subordinate Officers............................................................................8
         5.5      Resignation and Removal.........................................................................8
         5.6      Vacancies.......................................................................................8
         5.7      Chairman of the Board and Vice Chairman of the Board............................................8
         5.8      President.......................................................................................8
         5.9      Vice Presidents.................................................................................9
         5.10     Secretary and Assistant Secretaries.............................................................9
         5.11     Treasurer and Assistant Treasurers..............................................................9
         5.12     Authority and Duties of Officers................................................................9
         5.13     Salaries.......................................................................................10

ARTICLE VI - CAPITAL STOCK.......................................................................................10

         6.1      Stock Certificates.............................................................................10
         6.2      Special Designation on Certificates............................................................10
         6.3      Lost Certificates..............................................................................10
         6.4      Transfer of Stock..............................................................................11
         6.5      Registered Stockholders........................................................................11
         6.6      Dividends......................................................................................11

ARTICLE VII - RECORDS AND REPORTS................................................................................11

         7.1      Maintenance and Inspection of Records..........................................................11
         7.2      Inspection by Directors........................................................................12
         7.3      Annual Statement to Stockholders...............................................................12
         7.4      Representation of Shares of Other Corporations.................................................12

ARTICLE VIII - INDEMNIFICATION...................................................................................12

         8.1      Indemnification of Directors and Officers......................................................12
         8.2      Indemnification of Others......................................................................13
         8.3      Insurance......................................................................................14

ARTICLE IX - GENERAL PROVISIONS..................................................................................14

         9.1      Checks.........................................................................................14
</TABLE>
                                       ii
<PAGE>
<TABLE>

       <S>                                                                                                       <C>
         9.2      Fiscal Year....................................................................................14
         9.3      Seal...........................................................................................14
         9.4      Manner of Giving Notice........................................................................14
         9.5      Transactions with Interested Parties...........................................................14

ARTICLE X - AMENDMENTS...........................................................................................15
</TABLE>

                                       iii

<PAGE>



                           AMENDED AND RESTATED BYLAWS
                                       OF
                           JUNO ONLINE SERVICES, INC.

                              ARTICLE I - OFFICES
                              -------------------

                  1.1 REGISTERED OFFICE. The registered office of Juno Online
Services, Inc. (the "Corporation") shall be in the City of Wilmington, County of
New Castle, State of Delaware. The name of the registered agent of the
Corporation at such location is Corporation Service Company.

                  1.2 OTHER OFFICES. The Corporation may also have offices at
such other places both within and without the State of Delaware as the Board of
Directors (or the "Board") may from time to time determine or the business of
the Corporation may require.

                     ARTICLE II - MEETINGS OF STOCKHOLDERS
                     -------------------------------------

                  2.1 PLACE OF MEETINGS. All meetings of the stockholders for 
the election of directors shall be held at such place as may be fixed from 
time to time by the Board of Directors, or at such other place either within 
or without the State of Delaware as shall be designated from time to time by 
the Board of Directors and stated in the notice of the meeting. Meetings of 
stockholders for any other purpose may be held at such time and place, within 
or without the State of Delaware, as shall be stated in the notice of the 
meeting or in a duly executed waiver of notice thereof. In the absence of any 
such designation, stockholders' meetings shall be held at the registered 
office of the Corporation.

                  2.2 ANNUAL MEETING. Annual meetings of stockholders shall be
held at such date and time as shall be designated from time to time by the Board
of Directors and stated in the notice of the meeting. At each annual meeting,
the stockholders shall elect directors to succeed those whose terms expire in
that year and shall transact such other business as may properly be brought
before the meeting.

                  Nominations of persons for election to the Board of Directors
and stockholders' proposals may be made at an annual meeting of stockholders (a)
pursuant to the Corporation's notice of meeting, (b) by or at the direction of
the Board of Directors or (c) by any stockholder of the Corporation who was a
stockholder of record at the time of giving of notice, who is entitled to vote
at the meeting and who complies with the notice provisions set forth in the
following sentence. For nominations and proposals to be properly brought before
an annual meeting by a stockholder pursuant to clause (c) in the preceding
sentence, the stockholder must have given notice thereof in writing to the
Secretary of the Corporation not later than the close of business on the one
hundred twentieth (120th) day preceding the meeting nor earlier than the close
of business on the one hundred fiftieth (150th) day preceding the meeting and
such notice must include the information relating to such nominee(s) that is
required to be disclosed in solicitations of proxies for election of directors
pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended
(the "Exchange Act"), including such person's written


<PAGE>

consent to being named in the proxy statement as a nominee and to serving as a
director if elected.

                  2.3 SPECIAL MEETING. Special meetings of the stockholders, for
any purpose or purposes, unless otherwise prescribed by statute or by the
Certificate of Incorporation, may be called only by the Board. Business
transacted at any special meeting of stockholders shall be limited to the
purposes stated in the notice.

                  2.4 NOTICE OF STOCKHOLDER'S MEETING. Written notice of
meetings with stockholders shall state the place, date and hour of the meeting
and shall be given to each stockholder entitled to vote at such meeting not
fewer than ten (10) nor more than sixty (60) days before the date of the
meeting. The notice shall specify the place, date, and hour of the meeting, and,
in the case of a special meeting, the purpose or purposes for which the meeting
is called.

                  2.5 FIXING RECORD DATE FOR STOCKHOLDER NOTICE. In order 
that the Corporation may determine the stockholders entitled to notice of or 
to vote at any meeting of stockholders or any adjournment thereof, or to 
express consent to corporate action in writing without a meeting, or entitled 
to receive payment of any dividend or other distribution or allotment of any 
rights, or entitled to exercise any rights in respect of any change, 
conversion or exchange of stock or for the purpose of any other lawful 
action, the Board of Directors may fix, in advance, a record date, which 
shall not be more than sixty (60) nor less than ten (10) days before the date 
of such meeting, nor more than sixty (60) days prior to any other action. A 
determination of stockholders of record entitled to notice of or to vote at a 
meeting of stockholders shall apply to any adjournment of the meeting; 
provided, however, that the Board of Directors may fix a new record date for 
the adjourned meeting.

                  2.6 LIST OF STOCKHOLDERS ENTITLED TO VOTE. The officer who has
charge of the stock ledger of the Corporation shall prepare and make, at least
ten (10) days before every meeting of stockholders, a complete list of the
stockholders entitled to vote at the meeting, arranged in alphabetical order,
and showing the address of each stockholder and the number of shares registered
in the name of each stockholder. Such list shall be open to the examination of
any stockholder, for any purpose germane to the meeting, during ordinary
business hours, for a period of at least ten (10) days prior to the meeting,
either at a place within the city where the meeting is to be held, which place
shall be specified in the notice of the meeting, or, if not so specified, at the
place where the meeting is to be held. The list shall also be produced and kept
at the time and place of the meeting during the whole time thereof, and may be
inspected by any stockholder who is present.

                  2.7 ADJOURNMENTS; NOTICE. Any meeting of stockholders may be
adjourned to any other time and to any other place at which a meeting of
stockholders may be held under these Bylaws by the stockholders present or
represented at the meeting and entitled to vote, although less than a quorum,
or, if no stockholder is present, by any officer entitled to preside at or to
act as Secretary of such meeting. It shall not be necessary to notify any
stockholder of any adjournment of less than thirty (30) days if the time and
place of the adjourned meeting are announced at the meeting at which adjournment
is taken. If the adjournment is for more than thirty (30) days, or if after the
adjournment a new record date is fixed for the adjourned meeting, a notice of
the adjourned meeting shall be given to each stockholder of record entitled to
vote at 

                                       2
<PAGE>

the meeting. At such adjourned meeting at which a quorum shall be present or
represented by proxy, the Corporation may transact any business which might have
been transacted at the original meeting.

                  2.8 WAIVER OF NOTICE. Whenever notice is required to be given
under any provision of the General Corporation Law of Delaware, the Certificate
of Incorporation or these Bylaws, a written waiver thereof, signed by the person
entitled to notice, whether before or after the time stated therein, shall be
deemed equivalent to notice. Attendance of a person at a meeting shall
constitute a waiver of notice of such meeting, except when the person attends a
meeting for the express purpose of objecting, at the beginning of the meeting,
to the transaction of any business because the meeting is not lawfully called or
convened. Neither the business to be transacted at, nor the purpose of, any
regular or special meeting of the stockholders need be specified in any written
waiver of notice unless so required by the Certificate of Incorporation or these
Bylaws.

                  2.9 QUORUM. Except as otherwise provided by law, the
Certificate of Incorporation or these Bylaws, the holders of 50% of the stock
issued and outstanding and entitled to vote thereat, present in person or
represented by proxy, shall constitute a quorum at all meetings of the
stockholders for the transaction of business. If, however, such quorum shall not
be present or represented at any meeting of the stockholders, the stockholders
entitled to vote thereat, present in person or represented by proxy, shall have
power to adjourn the meeting from time to time, without notice other than
announcement at the meeting, until a quorum shall be present or represented.

                  2.10 VOTING AND PROXIES. Each stockholder shall have one (1)
vote for each share of stock entitled to vote held of record by such stockholder
and a proportionate vote for each fractional share so held, unless otherwise
provided in the Certificate of Incorporation. Each stockholder of record
entitled to vote at a meeting of stockholders may vote or express such consent
or dissent in person or may authorize another person or persons to vote or act
for him by written proxy executed by the stockholder or his authorized agent and
delivered to the secretary of the Corporation. No such proxy shall be voted or
acted upon after three (3) years from the date of its execution, unless the
proxy expressly provides for a longer period.

                  2.11 ACTION AT MEETING. When a quorum is present at any
meeting, the holders of shares of stock representing a majority of the votes
cast on a matter (or if there are two (2) or more classes of stock entitled to
vote as separate classes, then in the case of each such class, the holders of
shares of stock of that class representing a majority of the votes cast on a
matter) shall decide any matter to be voted upon by the stockholders at such
meeting, except when a different vote is required by express provision of law,
the Certificate of Incorporation or these Bylaws. When a quorum is present at
any meeting, any election by stockholders shall be determined by a plurality of
the votes cast on the election.
 
                  2.12 GENERAL. Only such persons who are nominated in
accordance with the procedures set forth in this Article II shall be eligible to
serve as directors and only such business shall be conducted at a meeting of
stockholders as shall have been brought before the meeting in accordance with
the procedures set forth in this Article II. Except as otherwise provided by
law, the Certificate of Incorporation or these Bylaws, the chairman of the
meeting shall have the



                                       3
<PAGE>

power and duty to determine whether a nomination or any business proposed to be
brought before the meeting was made or proposed, as the case may be, in
accordance with the procedures set forth in this Article II and, if any proposed
nomination or business is not in compliance herewith, to declare that such
defective proposal or nomination shall be disregarded.

                  Notwithstanding the foregoing provisions of this Article II, a
stockholder shall also comply with all applicable requirements of the Exchange
Act and the rules and regulations thereunder with respect to the matters set
forth herein. Nothing in this Article II shall be deemed to affect any rights
(a) of stockholders to request inclusion of proposals in the Corporation's proxy
statement pursuant to Rule 14a-8 under the Exchange Act or (b) of the holders of
any series of Preferred Stock to elect directors under specified circumstances.

                            ARTICLE III - DIRECTORS
                            -----------------------

                  3.1 GENERAL POWERS. The business and affairs of the
Corporation shall be managed by or under the direction of a Board of Directors,
who may exercise all of the powers of the Corporation except as otherwise
provided by law or the Certificate of Incorporation. In the event of a vacancy
in the Board of Directors, the remaining directors, except as otherwise provided
by law, may exercise the powers of the full Board until the vacancy is filled.

                  3.2 NUMBER; ELECTION AND QUALIFICATION. The number of
directors which shall constitute the whole Board of Directors shall be
determined by resolution of the stockholders or the Board of Directors, but in
no event shall be less than three (3) nor more than thirteen (13). The Board
shall be divided into three (3) classes as nearly equal in number as possible.
The members of each class shall be elected for a term of three (3) years and
until their successors are elected and qualified. The Board of Directors shall
be classified in accordance with the provisions of the Corporation's Certificate
of Incorporation. Directors need not be stockholders of the Corporation.

                  3.3 ENLARGEMENT OR REDUCTION OF THE BOARD. The number of
directors may only be increased or decreased if at least 66.67% of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors (considered for this purpose as one
class) cast at a meeting of the stockholders called for that purpose approve
such increase or decrease; provided, however, that no decrease in the number of
directors shall have the effect of shortening the term of an incumbent director.

                  3.4 TENURE. Each director shall hold office in accordance with
the provisions of the Corporation's Certificate of Incorporation.

                  3.5 VACANCIES. Vacancies occurring in the Board of Directors
for any reason and newly created directorships shall be filled by a vote of a
majority of the remaining members of the Board, even if less than a quorum, at
any meeting of the Board of Directors. A director so chosen shall hold office
for the remainder of the full term of the director for which the vacancy was
created or occurred and until such director's successor shall have been duly
elected and qualified. If there are no directors in office, then an election of
directors may be held in the manner provided by statute.

                                       4
<PAGE>

                  3.6 RESIGNATION. Any director may resign by delivering his
written resignation to the Corporation at its principal office or to the
president or secretary. Such resignation shall be effective upon receipt unless
it is specified to be effective at some other time or upon the happening of some
other event.

                  3.7 REGULAR MEETINGS. Regular meetings of the Board of
Directors may be held without notice at such time and place, either within or
without the State of Delaware, as shall be determined from time to time by the
Board of Directors; provided that any director who is absent when such a
determination is made shall be given notice of the determination. A regular
meeting of the Board of Directors may be held without notice immediately after,
and at the same place as, the annual meeting of stockholders.

                  3.8 SPECIAL MEETINGS. Special meetings of the Board of
Directors may be held at any time and place, within or without the State of
Delaware, designated in a call by the Chairman of the Board, president, two (2)
or more directors, or by one (1) director in the event that there is only a
single director in office.

                  3.9 NOTICE OF SPECIAL MEETINGS. Notice of any special meeting
of directors shall be given to each director by the secretary or by the officer
or one of the directors calling the meeting. Notice shall be duly given to each
director (a) by giving notice to such director in person or by telephone at
least 48 hours in advance of the meeting, (b) by sending a facsimile, telegram
or telex, or delivering written notice by hand, to his last known business or
home address at least 48 hours in advance of the meeting, or (c) by mailing
written notice to his last known business or home address at least 72 hours in
advance of the meeting. A notice or waiver of notice of a meeting of the Board
of Directors need not specify the purposes of the meeting.

                  3.10 WAIVER OF NOTICE. Whenever notice is required to be given
under any provision of the General Corporation Law of Delaware or of the
Certificate of Incorporation or these Bylaws, a written waiver thereof, signed
by the person entitled to notice, whether before or after the time stated
therein, shall be deemed equivalent to notice. Attendance of a person at a
meeting shall constitute a waiver of notice of such meeting, except when the
person attends a meeting for the express purpose of objecting, at the beginning
of the meeting, to the transaction of any business because the meeting is not
lawfully called or convened. Neither the business to be transacted at, nor the
purpose of, any regular or special meeting of the directors, or members of a
committee of directors, need be specified in any written waiver of notice unless
so required by the Certificate of Incorporation or these Bylaws.

                  3.11 MEETINGS BY TELEPHONE CONFERENCE CALLS. Directors or any
members of any committee designated by the directors may participate in a
meeting of the Board of Directors or such committee by means of conference
telephone or similar communications equipment by means of which all persons
participating in the meeting can hear each other, and participation by such
means shall constitute presence in person at such meeting.

                  3.12 QUORUM. A majority of the authorized number of directors
shall constitute a quorum at all meetings of the Board of Directors. In the
event one or more of the directors shall be disqualified to vote at any meeting,
then the required quorum shall be reduced by one for 



                                       5
<PAGE>

each such director so disqualified; provided, however, that in no case shall
less than one-third (1/3) of the authorized number constitute a quorum.

                  3.13 ADJOURNED MEETING. If a quorum is not present at any
regular or special meeting of the Board of Directors, then the directors present
thereat may adjourn the meeting from time to time, without notice other than
announcement at the meeting, until a quorum is present.

                  3.14 ACTION AT MEETING. At any meeting of the Board of
Directors at which a quorum is present, the vote of a majority of those present
shall be sufficient to take any action, unless a different vote is specified by
law, the Certificate of Incorporation, these Bylaws or any contractual
arrangements among the stockholders.

                  3.15 ACTION BY CONSENT. Unless otherwise restricted by the
Certificate of Incorporation or these Bylaws, any action required or permitted
to be taken at any meeting of the Board of Directors or of any committee of the
Board of Directors may be taken without a meeting, if all members of the Board
or committee, as the case may be, consent to the action in writing, and the
written consents are filed with the minutes of proceedings of the Board or
committee.

                  3.16 FEES AND COMPENSATION OF DIRECTORS. Unless otherwise
restricted by the Certificate of Incorporation or these Bylaws, directors may be
paid such compensation for their services and such reimbursement for expenses of
attendance at meetings as the Board of Directors may from time to time
determine. No such payment shall preclude any director from serving the
Corporation or any of its parent or subsidiary corporations in any other
capacity and receiving compensation for such service.

                  3.17 APPROVAL OF LOANS TO OFFICERS. The Corporation may lend
money to, or guarantee any obligation of, or otherwise assist any officer or
other employee of the Corporation or of its subsidiary, including any officer or
employee who is a director of the Corporation or its subsidiary, whenever, in
the judgment of the directors, such loan, guaranty or assistance may reasonably
be expected to benefit the Corporation. The loan, guaranty or other assistance
may be with or without interest and may be unsecured, or secured in such manner
as the Board of Directors shall approve, including, without limitation, a pledge
of shares of stock of the Corporation. Nothing in this section contained shall
be deemed to deny, limit or restrict the powers of guaranty or warranty of the
Corporation at common law or under any statute.

                  3.18 REMOVAL. Except as otherwise provided by the General
Corporation Law of Delaware, a director or the entire Board of Directors may
only be removed in accordance with the provisions of the Corporation's
Certificate of Incorporation.

                            ARTICLE IV - COMMITTEES
                            -----------------------

                  4.1 ENUMERATION OF COMMITTEES. The Board of Directors may, by
resolution passed by a majority of the whole Board, designate one (1) or more
committees, each committee to consist of one (1) or more of the directors of the
Corporation. The Board may designate one (1) or more directors as alternate
members of any committee, who may replace any absent or 




                                       6
<PAGE>

disqualified member at any meeting of the committee. In the absence or
disqualification of a member of a committee, the member or members of the
committee present at any meeting and not disqualified from voting, whether or
not he or they constitute a quorum, may unanimously appoint another member of
the Board of Directors to act at the meeting in the place of any such absent or
disqualified member. Any such committee, to the extent provided in the
resolution of the Board of Directors and subject to the provisions of the
General Corporation Law of Delaware, shall have and may exercise all the powers
and authority of the Board of Directors in the management of the business and
affairs of the Corporation and may authorize the seal of the Corporation to be
affixed to all papers which may require it. Each such committee shall keep
minutes and make such reports as the Board of Directors may from time to time
request. Except as the Board of Directors may otherwise determine, any committee
may make rules for the conduct of its business, but unless otherwise provided by
the directors or in such rules, its business shall be conducted as nearly as
possible in the same manner as is provided in these Bylaws for the Board of
Directors.

                  4.2 COMMITTEE MINUTES. Each committee shall keep regular
minutes of its meetings and report the same to the Board of Directors when
required.

                  4.3 MEETINGS AND ACTION OF COMMITTEES. Meetings and action of
committee shall be governed by, and held and taken in accordance with, the
provisions of Article III of these Bylaws, Section 3.7 (regular meetings),
Section 3.8 (special meetings), Section 3.9 (notice of special meetings),
Section 3.10 (waiver of notice), Section 3.11 (meetings by telephone conference
calls), Section 3.12 (quorum), Section 3.13 (adjourned meeting), Section 3.14
(action at meeting) and Section 3.15 (action by consent), with such changes in
the context of these Bylaws as are necessary to substitute the committee and its
members for the Board of Directors and its members; provided, however, that the
time of regular meetings of committees may also be called by resolution of the
Board of Directors and that notice of special meetings of committees shall also
be given to all alternate members, who shall have the right to attend all
meetings of the committee. The Board of Directors may adopt rules for the
government of any committee not inconsistent with the provisions of these
Bylaws.

                              ARTICLE V - OFFICERS
                              --------------------

                  5.1 ENUMERATION OF OFFICERS. The officers of the Corporation
shall be chosen by the Board of Directors and consist of a president, one or
more vice presidents, a secretary and a treasurer or chief financial officer.
The Board of Directors may elect from among its members a Chairman of the Board
and a Vice Chairman of the Board.

                  5.2 ELECTION OF OFFICERS. The officers of the Corporation,
except such officers as may be appointed in accordance with the provisions of
Section 5.4 or 5.6 of these Bylaws, shall be chosen by the Board of Directors,
subject to the rights, if any, of an officer under any contract of employment.

                  5.3 QUALIFICATION AND TENURE. No officer need be a
stockholder. Any two (2) or more offices may be held by the same person. Except
as otherwise provided by law, by the Certificate of Incorporation or by these
Bylaws, each officer shall hold office until his successor 



                                       7
<PAGE>

is elected and qualified, unless a different term is specified in the vote
choosing or appointing him, or until his earlier death, resignation or removal.

                  5.4 SUBORDINATE OFFICERS. The Board of Directors may appoint,
or empower the president to appoint, such other officers and agents as the
business of the Corporation may require, each of whom shall hold office for such
period, have such authority, and perform such duties as are provided in these
Bylaws or as the Board of Directors may from time to time determine.

                  5.5 RESIGNATION AND REMOVAL. Any officer may resign by
delivering his written resignation to the Corporation at its principal office or
to the president or secretary. Such resignation shall be effective upon receipt
unless it is specified to be effective at some other time or upon the happening
of some other event.

                  Subject to the rights, if any, of an officer under any 
contract of employment, any officer may be removed at any time, with or 
without cause, by vote of a majority of the entire number of directors then 
in office.

                  Except as the Board of Directors may otherwise determine, no
officer who resigns or is removed shall have any right to any compensation as an
officer for any period following his resignation or removal, or any right to
damages on account of such removal, whether his compensation be by the month or
by the year or otherwise, unless such compensation is expressly provided in a
duly authorized written agreement with the Corporation.

                  5.6 VACANCIES. The Board of Directors may fill any vacancy
occurring in any office for any reason and may, in its discretion, leave
unfilled for such period as it may determine any offices other than those of
president, treasurer and secretary. Each such successor shall hold office for
the unexpired term of his predecessor and until his successor is elected and
qualified, or until his earlier death, resignation or removal.

                  5.7 CHAIRMAN OF THE BOARD AND VICE CHAIRMAN OF THE BOARD. The
Board of Directors may appoint a Chairman of the Board and may, but is not
obligated to, designate the Chairman of the Board as chief executive officer. If
the Board of Directors appoints a Chairman of the Board, he shall perform such
duties and possess such powers as are assigned to him by the Board of Directors.
Unless otherwise provided by the Board of Directors, the Chairman of the Board
shall preside at all meetings of the stockholders and at all meetings of the
Board of Directors. If the Board of Directors appoints a Vice Chairman of the
Board, he shall, in the absence or disability of the Chairman of the Board,
perform the duties and exercise the powers of the Chairman of the Board and
shall perform such other duties and possess such other powers as may from time
to time be vested in him by the Board of Directors.

                  5.8 PRESIDENT. The president shall, subject to the direction
of the Board of Directors, have general charge and supervision of the business
of the Corporation. Unless the Board of Directors has designated the Chairman of
the Board or another officer as chief executive officer, the president shall be
the chief executive officer of the Corporation. The president shall perform such
other duties and shall have such other powers as the Board of Directors may from
time to time prescribe.

                                       8
<PAGE>

                  5.9 VICE PRESIDENTS. Any vice president shall perform such
duties and possess such powers as the Board of Directors or the president may
from time to time prescribe. In the event of the absence, inability or refusal
to act of the president, the vice president (or if there shall be more than one
(1), the vice presidents in the order determined by the Board of Directors)
shall perform the duties of the president and when so performing shall have all
the powers of and be subject to all the restrictions upon the president. The
Board of Directors may assign to any vice president the title of executive vice
president, senior vice president or any other title selected by the Board of
Directors.

                  5.10 SECRETARY AND ASSISTANT SECRETARIES. The secretary shall
perform such duties and shall have such powers as the Board of Directors or the
president may from time to time prescribe. In addition, the secretary shall
perform such duties and have such powers as are incident to the office of the
secretary, including without limitation, the duty and power to give notices of
all meetings of stockholders and special meetings of the Board of Directors, to
attend all meetings of stockholders and the Board of Directors and keep a record
of the proceedings, to maintain a stock ledger and prepare lists of stockholders
and their addresses as required, to be custodian of corporate records and the
corporate seal and to affix and attest to the same on documents.

                  Any assistant secretary shall perform such duties and possess
such powers as the Board of Directors, the president or the secretary may from
time to time prescribe. In the event of the absence, inability or refusal to act
of the secretary, the assistant secretary, (or if there shall be more than one
(1), the assistant secretaries in the order determined by the Board of
Directors) shall perform the duties and exercise the powers of the secretary. 

                  In the absence of the secretary or any assistant secretary at
any meeting of stockholders or directors, the person presiding at the meeting
shall designate a temporary secretary to keep a record of the meeting.

                  5.11 TREASURER AND ASSISTANT TREASURERS. The treasurer shall
perform such duties and shall have such powers as may from time to time be
assigned to him by the Board of Directors or the president. In addition, the
treasurer or chief financial officer shall perform such duties and have such
powers as are incident to the office of treasurer, including without limitation,
the duty and power to keep and be responsible for all funds and securities of
the Corporation, to deposit funds of the Corporation in depositories selected in
accordance with these Bylaws, to disburse such funds as ordered by the Board of
Directors, to make proper accounts of such funds, and to render as required by
the Board of Directors statements of all such transactions and of the financial
condition of the Corporation.

                  The assistant treasurers shall perform such duties and possess
such powers as the Board of Directors, the president or the treasurer may from
time to time prescribe. In the event of the absence, inability or refusal to act
of the treasurer, the assistant treasurer, (or if there shall be more than one
(1), the assistant treasurers in the order determined by the Board of Directors)
shall perform the duties and exercise the powers of the treasurer.

                  5.12 AUTHORITY AND DUTIES OF OFFICERS. In addition to the
foregoing authority and duties, all officers of the Corporation shall
respectively have such authority and perform 



                                       9
<PAGE>

such duties in the management of the business of the Corporation as may be
designated from time to time by the Board of Directors or the stockholders.

                  5.13 SALARIES. Officers of the Corporation shall be entitled
to such salaries, compensation or reimbursement as shall be fixed or allowed
from time to time by the Board of Directors.

                           ARTICLE VI - CAPITAL STOCK
                           --------------------------

                  6.1 STOCK CERTIFICATES. The shares of the Corporation shall 
be represented by certificates, provided that the Board of Directors of the 
Corporation may provide by resolution or resolutions that some or all of any 
or all classes or series of its stock shall be uncertificated shares. Any 
such resolution shall not apply to shares represented by a certificate until 
such certificate is surrendered to the Corporation. Notwithstanding the 
adoption of such a resolution by the Board of Directors, every holder of 
stock represented by certificates and upon request every holder of 
uncertificated shares shall be entitled to have a certificate, signed by, or 
in the name of the Corporation by, the Chairman or Vice Chairman of the Board 
of Directors, or the president or a vice president and the treasurer or an 
assistant treasurer, or the secretary or an assistant secretary of the 
Corporation, certifying the number of shares owned by such holder in the 
Corporation. Any of or all the signatures on the certificate may be facsimile 
signature(s). In case any officer, transfer agent or registrar who has signed 
or whose facsimile signature has been placed upon a certificate shall have 
ceased to be such officer, transfer agent or registrar before such 
certificate is issued, it may be issued by the Corporation with the same 
effect as if such individual were such officer, transfer agent or registrar 
at the date of issue.

                  6.2 SPECIAL DESIGNATION ON CERTIFICATES. If the Corporation 
shall be authorized to issue more than one class of stock or more than one 
series of any class, the powers, designations, preferences and relative, 
participating, optional or other special rights of each class of stock or 
series thereof and the qualification, limitations or restrictions or such 
preferences and/or rights shall be set forth in full or summarized on the 
face or back of the certificate which the Corporation shall issue to 
represent such class or series of stock, provided that, except as otherwise 
provided in Section 202 of the General Corporation Law of Delaware, in lieu 
of the foregoing requirements, there may be set forth on the face or back of 
the certificate which the Corporation shall issue to represent such class or 
series of stock, a statement that the Corporation will furnish without charge 
to each stockholder who so requests the powers, designations, preferences and 
relative, participating, optional or other special rights of each class of 
stock or series thereof and the qualifications, limitations or restrictions 
of such preferences and/or rights.

                  6.3 LOST CERTIFICATES. The Board of Directors may direct a 
new certificate or certificates to be issued in place of any certificate or 
certificates theretofore issued by the Corporation alleged to have been lost, 
stolen or destroyed, upon the making of an affidavit of that fact by the 
person claiming the certificate of stock to be lost, stolen or destroyed. 
When authorizing such issue of a new certificate or certificates, the Board 
of Directors may, in its discretion and as a condition precedent to the 
issuance thereof, require the owner of such lost, stolen or destroyed 
certificate or certificates, or his legal representative, to advertise the 
same in such manner as it shall require and/or give the Corporation a bond in 
such sum as it may direct as

                                       10
<PAGE>

indemnity against any claim that may be made against the Corporation with
respect to the certificate alleged to have been lost, stolen or destroyed.

                  6.4 TRANSFER OF STOCK. Upon surrender to the Corporation or
the transfer agent of the Corporation of a certificate for shares duly endorsed
or accompanied by proper evidence of succession, assignation or authority to
transfer, it shall be the duty of the Corporation to issue a new certificate to
the person entitled thereto, cancel the old certificate and record the
transaction upon its books.

                  6.5 REGISTERED STOCKHOLDERS. The Corporation shall be 
entitled to recognize the exclusive right of a person registered on its books 
as the owner of shares to receive dividends, and to vote as such owner, and 
to hold liable for calls and assessments a person registered on its books as 
the owner of shares and shall not be bound to recognize any equitable or 
other claim to or interest in such share or shares on the part of any other 
person, whether or not it shall have express or other notice thereof, except 
as otherwise provided by the laws of Delaware.

                  6.6 DIVIDENDS. Dividends upon the capital stock of the
Corporation, subject to the provisions of the Certificate of Incorporation, if
any, may be declared by the Board of Directors at any regular or special
meeting, pursuant to law. Dividends may be paid in cash, in property, or in
shares of the capital stock, subject to the provisions of the Certificate of
Incorporation.

                  Before payment of any dividend, there may be set aside out of
any funds of the Corporation available for dividends such sum or sums as the
directors from time to time, in their absolute discretion, think proper as a
reserve or reserves to meet contingencies, or for equalizing dividends, or for
repairing or maintaining any property of the Corporation, or for such other
purposes as the directors shall think conducive to the interest of the
Corporation, and the directors may modify or abolish any such reserve in the
manner in which it was created.

                       ARTICLE VII - RECORDS AND REPORTS
                       ---------------------------------

                  7.1 MAINTENANCE AND INSPECTION OF RECORDS. The Corporation
shall, either at its principal executive office or at such place or places as
designated by the Board of Directors, keep a record of its stockholders listing
their names and addresses and the number and class of shares held by each
stockholder, a copy of these Bylaws as amended to date, accounting books, and
other records.

                  Any stockholder of record, in person or by attorney or other
agent, shall, upon written demand under oath stating the purpose thereof, have
the right during the usual hours of business to inspect for any proper purpose
the Corporation's stock ledger, a list of its stockholders, and its other books
and records and to make copies or extracts therefrom. A proper purpose shall
mean a purpose reasonably related to such person's interest as a stockholder. In
every instance where an attorney or other agent is the person who seeks the
right to inspection, the demand under oath shall be accompanied by a power of
attorney or such other writing that authorizes the attorney or other agent to so
act on behalf of the stockholder. The demand under



                                       11
<PAGE>

oath shall be directed to the Corporation at its registered office in Delaware
or at its principal place of business.

                  The officer who has charge of the stock ledger of the
Corporation shall prepare and make, at least ten (10) days before every meeting
of stockholders, a complete list of the stockholders entitled to vote at the
meeting, arranged in alphabetical order, and showing the address of each
stockholder and the number of shares registered in the name of each stockholder.
Such list shall be opened to the examination of any stockholder, for any purpose
germane to the meeting, during ordinary business hours, for a period of at least
ten (10) days prior to the meeting, either at a place within the city where the
meeting is to be held, which place shall be specified in the notice of the
meeting, or, if not so specified, at the place where the meeting is to be held.
The list shall also be produced and kept at the time and place of the meeting
during the whole time thereof, and may be inspected by any stockholder who is
present.

                  7.2 INSPECTION BY DIRECTORS. Any director shall have the right
to examine the Corporation's stock ledger, a list of its stockholders, and its
other books and records for a purpose reasonably related to his position as a
director. The Court of Chancery is hereby vested with the exclusive jurisdiction
to determine whether a director is entitled to the inspection sought. The Court
may summarily order the Corporation to permit the director to inspect any and
all books and records, the stock ledger, and the stock list and to make copies
or extracts therefrom. The Court may, in its discretion, prescribe any
limitations or conditions with reference to the inspection, or award such other
and further relief as the Court may deem just and proper.

                  7.3 ANNUAL STATEMENT TO STOCKHOLDERS. The Board of Directors
or, if designated by the Board of Directors, the president, shall present at
each annual meeting, and at any special meeting of the stockholders when called
for by vote of the stockholders, a full and clear statement of the business and
condition of the Corporation.

                  7.4 REPRESENTATION OF SHARES OF OTHER CORPORATIONS. The 
Chairman of the Board of Directors, the president, any vice president, the 
treasurer, the secretary or assistant secretary of the Corporation, or any 
other person authorized by the Board of Directors or the president or a vice 
president, is authorized to vote, represent, and exercise on behalf of this 
Corporation all rights incident to any and all shares of any other 
corporation or corporations standing in the name of this Corporation. The 
authority granted herein may be exercised either by such person directly or 
by any other persons authorized to do so by proxy or power of attorney duly 
executed by such person having the authority.

                         ARTICLE VIII - INDEMNIFICATION
                         ------------------------------

                  8.1 INDEMNIFICATION OF DIRECTORS AND OFFICERS. The 
Corporation shall, to the fullest extent authorized under the laws of the 
State of Delaware, as those laws may be amended and supplemented from time to 
time, indemnify any director or officer made, or threatened to be made, a 
party to an action or proceeding, whether criminal, civil, administrative or 
investigative, by reason of being a director or officer of the Corporation or 
a predecessor corporation. The indemnification provided for in this Section 
8.1 shall: (a) not be deemed exclusive of any other rights to which those 
indemnified may be entitled under any bylaw, agreement or vote of

                                       12
<PAGE>

stockholders or disinterested directors or otherwise, both as to action in their
official capacities and as to action in another capacity while holding such
office, (b) continue as to a person who has ceased to be a director, and (c)
inure to the benefit of the heirs, executors and administrators of such a
person. The Corporation's obligation to provide indemnification under this
Section 8.1 shall be offset to the extent of any other source of indemnification
or any otherwise applicable insurance coverage under a policy maintained by the
Corporation or any other person.

                  Expenses incurred by a director or officer of the Corporation
in defending a civil or criminal action, suit or proceeding by reason of the
fact that such individual is or was a director of the Corporation (or was
serving at the Corporation's request as a director or officer of another
corporation) shall be paid by the Corporation in advance of the final
disposition of such action, suit or proceeding upon receipt of an undertaking by
or on behalf of such director to repay such amount if it shall ultimately be
determined that such individual is not entitled to be indemnified by the
Corporation as authorized by relevant sections of the General Corporation Law of
Delaware. Notwithstanding the foregoing, the Corporation shall not be required
to advance such expenses to an agent who is a party to an action, suit or
proceeding brought by the Corporation and approved by a majority of the Board of
Directors of the Corporation which alleges willful misappropriation of corporate
assets by such agent, disclosure of confidential information in violation of
such agent's fiduciary or contractual obligations to the Corporation or any
other willful and deliberate breach in bad faith of such agent's duty to the
Corporation or its stockholders.

                  The foregoing provisions of this Section 8.1 shall be deemed
to be a contract between the Corporation and each director who serves in such
capacity at any time while this bylaw is in effect, and any repeal or
modification thereof shall not affect any rights or obligations then existing
with respect to any state of facts then or theretofore existing or any action,
suit or proceeding theretofore or thereafter brought based in whole or in part
upon any such state of facts.

                  To assure indemnification under this Section 8.1 of all
directors and officers who are determined by the Corporation or otherwise to be
or to have been "fiduciaries" of any employee benefit plan of the Corporation
which may exist from time to time, Section 145 of the General Corporation Law of
Delaware shall, for the purposes of this Article VIII, be interpreted as
follows: an "other enterprise" shall be deemed to include such an employee
benefit plan, including, without limitation, any plan of the Corporation which
is governed by the Act of Congress entitled "Employee Retirement Income Security
Act of 1974," as amended from time to time; the Corporation shall be deemed to
have requested a person to serve an employee benefit plan where the performance
by such person of his duties to the Corporation also imposes duties on, or
otherwise involves services by, such person to the plan or participants or
beneficiaries of the plan; excise taxes assessed on a person with respect to an
employee benefit plan pursuant to such Act of Congress shall be deemed "fines."

                  8.2 INDEMNIFICATION OF OTHERS. The Corporation shall have the
power, to the extent and in the manner permitted by the General Corporation Law
of Delaware, to indemnify each of its employees and agents (other than directors
and officers) against expenses (including attorneys' fees), judgments, fines,
settlements, and other amounts actually and reasonably 



                                       13
<PAGE>

incurred in connection with any proceeding, arising by reason of the fact that
such person is or was an agent of the Corporation. For purposes of this Section
8.2, an "employee" or "agent" of the Corporation (other than a director or
officer) includes any person (a) who is or was an employee or agent of the
Corporation, (b) who is or was serving at the request of the Corporation as an
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise, or (c) who was an employee or agent of a corporation which was
a predecessor corporation of the Corporation or of another enterprise at the
request of such predecessor corporation.

                  8.3 INSURANCE. The Corporation may purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the Corporation, or is or was serving at the request of the Corporation
as a director, officer, employee or agent of another corporation, partnership,
joint venture, trust or other enterprise against any liability asserted against
him and incurred by him in any such capacity, or arising out of his status as
such, whether or not the Corporation would have the power to indemnify him
against such liability under the provisions of the General Corporation Law of
Delaware.

                        ARTICLE IX - GENERAL PROVISIONS
                        -------------------------------

                  9.1 CHECKS. All checks or demands for money and notes of the
Corporation shall be signed by such officer or officers or such other person or
persons as the Board of Directors may from time to time designate.

                  9.2 FISCAL YEAR. The fiscal year of the Corporation shall end
on December 31, unless otherwise fixed by resolution of the Board of Directors.

                  9.3 SEAL. The Board of Directors may adopt a corporate seal
having inscribed thereon the name of the Corporation, the year of its
organization and the words "Corporate Seal, Delaware." The seal may be used by
causing it or a facsimile thereof to be impressed or affixed or reproduced or
otherwise.

                  9.4 MANNER OF GIVING NOTICE. Whenever, under the provisions of
the General Corporation Law of Delaware, the Certificate of Incorporation or
these Bylaws, notice is required to be given to any director or stockholder, it
shall not be construed to mean personal notice, but such notice may be given in
writing, by mail, addressed to such director or stockholder, at his address as
it appears on the records of the Corporation, with postage thereon prepaid, and
such notice shall be deemed to be given at the time when the same shall be
deposited in the United States mail. Notice to directors may also be given by
telegram. An affidavit of the secretary or an assistant secretary or of the
transfer agent of the Corporation that the notice has been given shall, in the
absence of fraud, be prima facie evidence of the facts stated therein.

                  9.5 TRANSACTIONS WITH INTERESTED PARTIES. No contract or
transaction between the Corporation and one (1) or more of the directors or
officers, or between the Corporation and any other corporation, partnership,
association, or other organization in which one or more of the directors or
officers are directors or officers, or have a financial interest, shall be void
or voidable solely for this reason, or solely because such director or officer
is present at or participates in the



                                       14
<PAGE>

meeting of the Board of Directors or a committee of the Board of Directors which
authorizes the contract or transaction or solely because his, her or their votes
are counted for such purpose, if:

                           (1) The material facts as to his or her relationship
or interest and as to the contract or transaction are disclosed or are known to
the Board of Directors or the committee, and the Board or committee in good
faith authorizes the contract or transaction by the affirmative vote of a
majority of the disinterested directors, even though the disinterested directors
be less than a quorum;

                           (2) The material facts as to his or her relationship
or interest and as to the contract or transaction are disclosed or are known to
the stockholders entitled to vote thereon, and the contract or transaction is
specifically approved in good faith by vote of the stockholders; or

                           (3) The contract or transaction is fair as to the
Corporation as of the time it is authorized, approved or ratified, by the Board
of Directors, a committee of the Board of Directors, or the stockholders. Common
or interested directors may be counted in determining the presence of a quorum
at a meeting of the Board of Directors or of a committee which authorizes the
contract or transaction.

                             ARTICLE X - AMENDMENTS
                             ----------------------

                  Except as set forth below, the original or other bylaws of the
Corporation may be adopted, amended or repealed by a majority of the
stockholders entitled to vote; provided, however, that the Corporation may, in
its Certificate of Incorporation, confer the power to adopt, amend or repeal
bylaws upon the directors. The fact that such power has been so conferred upon
the directors shall not divest the stockholders of the power, nor limit the
power to adopt, amend or repeal bylaws.

                  Notwithstanding any other provision of law, the Certificate of
Incorporation or these Bylaws, and notwithstanding the fact that a lesser
percentage may be specified by law, the affirmative vote of the holders of at
least 66.67% of the votes which all the stockholders would be entitled to cast
at any annual election of directors or class of directors shall be required to
amend or repeal, or to adopt any provision inconsistent with, Article II and
Sections 3.2 and 3.3 of these Bylaws.





                                       15
<PAGE>


                         CERTIFICATE OF ADOPTION BY THE
                                  SECRETARY OF
                           JUNO ONLINE SERVICES, INC.


                  The undersigned, Richard Buchband, hereby certifies that he is
the duly elected and acting Secretary of Juno Online Services, Inc., a Delaware
corporation (the "Corporation"), and that the Bylaws attached hereto constitute
the Bylaws of said Corporation as duly adopted by the Board of Directors on
April ____, 1999 and approved by the stockholders of the Corporation on
May __, 1999.

                  IN WITNESS WHEREOF, the undersigned has hereunto subscribed
his name this ____day of May, 1999.



                                                 --------------------------
                                                 Richard Buchband
                                                 Secretary




<PAGE>
                                                                     Exhibit 5.1






                                     May 5, 1999



Juno Online Services, Inc.
1540 Broadway
New York, NY 10036

                  Re:      JUNO ONLINE SERVICES, INC. -- REGISTRATION STATEMENT
                           ON FORM S-1 FOR 6,500,000 SHARES OF COMMON STOCK
                           ------------------------------------------------

Ladies and Gentlemen:

                  We have acted as counsel to Juno Online Services, Inc., a
Delaware corporation (the "Company"), in connection with the proposed issuance
and sale by the Company of up to 6,500,000 shares of the Company's Common Stock
(the "Shares") pursuant to the Company's Registration Statement on Form S-1 (the
"Registration Statement") filed with the Securities and Exchange Commission
under the Securities Act of 1933, as amended (the "Act").

                  This opinion is being furnished in accordance with the
requirements of Item 16(a) of Form S-1.

                  We have reviewed the Company's charter documents and the
corporate proceedings taken by the Company in connection with the issuance and
sale of the Shares. Based on such review, we are of the opinion that the Shares
have been duly authorized, and if, as and when issued in accordance with the
Registration Statement and the related prospectus (as amended and supplemented
through the date of issuance) will be legally issued, fully paid and
nonassessable.

                  We consent to the filing of this opinion letter as Exhibit 5.1
to the Registration Statement and to the reference to this firm under the
caption "Legal Matters" in the prospectus which is part of the Registration
Statement. In giving this consent, we do not thereby admit that we are within
the category of persons whose consent is required under Section 7 of the Act,
the rules and regulations of the Securities and Exchange Commission promulgated
thereunder, or Item 509 of Regulation S-K.



<PAGE>
Juno Online Services, Inc.                                                Page 2
May 5, 1999

                  This opinion letter is rendered as of the date first written
above and we disclaim any obligation to advise you of facts, circumstances,
events or developments which hereafter may be brought to our attention and which
may alter, affect or modify the opinion expressed herein. Our opinion is
expressly limited to the matters set forth above and we render no opinion,
whether by implication or otherwise, as to any other matters relating to the
Company or the Shares.

                                   Very truly yours,



                                /s/ Brobeck, Phleger & Harrison LLP
                               -------------------------------------
                                    BROBECK, PHLEGER & HARRISON LLP


<PAGE>

                                                                Exhibit 10.12(b)

                              EMPLOYMENT AGREEMENT


         AGREEMENT dated as of 26 day of APRIL, 1999, by and between Juno
Online Services, Inc., a Delaware corporation ("Company"), and Charles Ardai
(the "Employee").

         WHEREAS, the Company desires to continue to retain the Employee on the
terms and conditions hereinafter set forth, and the Employee is willing to
continue employment by the Company upon such terms and conditions;

         NOW, THEREFORE, in consideration of the foregoing and in consideration
of their mutual promises and agreements contained herein, the parties hereto
agree as follows:

         1. EMPLOYMENT

         Employment has commenced, and may be terminated by either party at any
time, for any reason, upon 30 days notice (the "Notice Period"), which notice
may be given either verbally or in writing. Notwithstanding the foregoing, the
Company may elect to terminate immediately upon notice, except that in this
event, the compensation and benefits set forth in Section 2 shall be continued
for the duration of the Notice Period. The Employee acknowledges and agrees that
he is an employee at will, and that just as the Employee is free to resign at
any time, the Company has the right to terminate the employment relationship at
any time for any lawful reason. The Employee acknowledges and agrees that no
representative of the Company may verbally change the at will employment
relationship between the Employee and the Company. References to time periods in
this Agreement shall not be construed or interpreted as promising or
guaranteeing employment for any specific duration or until any specific date.

         2. COMPENSATION

         (a) BASE SALARY DURING THE COMPENSATION PERIOD. As compensation for the
Employee's services during the period beginning May 1, 1999 and ending on
December 31, 1999 (the "Compensation Period"), the Company shall pay the
Employee a base salary computed at an annual rate of $185,000 per year, prorated
to correspond to that portion of the Compensation Period during which the
Employee is actually employed with the Company, such base salary to be paid
semi-monthly.

         (b) SEMI-ANNUAL BONUS DURING THE COMPENSATION PERIOD. As compensation
for the Employee's services during the Compensation Period, the Company shall
pay the Employee a semi-annual bonus of $50,000 on January 1 and July 1 of each
year during the Compensation Period, provided that Employee is employed by the
Company on such date.

         (c) BASE SALARY AFTER THE COMPENSATION PERIOD. As of the end of the
Compensation Period, the Employee's base salary may be increased or decreased,
or the manner in which the Employee is compensated may be changed, in the sole
discretion of the Company. Any such change in compensation shall be deemed to
modify only this Section 2 of this Agreement, and all other provisions of this
Agreement shall remain in effect following such change in compensation. In the
absence of any such change, the Employee's base salary shall remain the same as
it was during the Compensation Period.

         (d) DISCRETIONARY SEMI-ANNUAL BONUS. In addition to the semi-annual
bonus to be paid to the Employee pursuant to Section 2(b), the Company may (or
may not) in its sole discretion pay the Employee an additional discretionary
bonus at such time. The award and amount of any such bonus shall be determined
by the Company in its sole discretion .

         (e) BONUS AFTER THE COMPENSATION PERIOD. As of the end of the
Compensation Period, the Employee's semi-annual bonus, may be increased,
decreased, or eliminated, or the manner in which the Employee is compensated may
be changed, in the sole discretion of the Company, expressed in writing.
Subsequent to the Compensation Period, the Company shall not have any obligation
to continue to pay a bonus to the Employee unless such an arrangement is
explicitly agreed to in writing by a duly authorized officer of the Company.

         (f) STANDARD COMPANY BENEFITS. In addition to the compensation outlined
elsewhere in this Section 2, the Company shall provide to the Employee all of
the benefits included in the Company's standard benefit package,




<PAGE>

which currently include medical (hospitalization and major medical), dental,
disability, life, and accidental death and dismemberment insurance. Most of the
cost of such benefits shall be borne by the Company. However, in the case of
coverage for the Employee himself, the Employee contributes a nominal pre-tax
amount to the cost of the medical insurance; if the Employee wishes to obtain
coverage for other qualified family members, and arranges with the Company's
insurance providers (through the Company's Human Resources staff) to obtain such
additional coverage, the Employee will also be required to contribute part of
the incremental cost of such coverage. Individual and dependent medical
insurance contribution amounts are determined on a set scale, based on both the
actual cost of the insurance and on the Employee's base salary. The required
contribution will be borne by the Employee by means of a voluntary salary
reduction in the amount of the contribution implemented by the Company at the
request of the Employee.

         The standard benefit package also currently includes a flexible
spending account plan and a 401(k) retirement plan, available to all qualified
full-time employees after a certain period of employment with the Company. The
401(k) retirement plan currently includes a matching program and a graded
vesting schedule; the Company does not contribute to the flexible spending
account plan, but the Employee may contribute pre-tax dollars. The Employee
agrees that the composition, providers, and all other aspects of the Company's
standard benefit package may be changed from time to time in the sole discretion
of the Management Company.

         (g) EXCLUSIVE COMPENSATION. The compensation and benefits described in
this Section 2 shall be the exclusive compensation due to the Employee from the
Company or any of its affiliates during or on account of the services of the
Employee. If directed by the Company, the Employee shall provide the services
described in this Agreement to one or more affiliates of the Company without
compensation other than as specified in this Section 2.

         3. DISCLOSURE TO THE COMPANY

         (a) DISCLOSURE OF INFORMATION TO THE COMPANY. The Employee shall
promptly disclose and deliver over to the Company, without additional
compensation, to the extent that such disclosure could reasonably be expected to
be of interest to the Company, in writing, or in such form and manner as the
Company may reasonably require:

                  (i) any and all algorithms, procedures, methods or techniques
directly related to electronic communication and/or electronic commerce or to
the Employee's work with the Company, and the essential ideas and principles
underlying such algorithms, procedures, methods or techniques, conceived,
originated, discovered, developed, evaluated, tested, or applied by the Employee
while employed by the Company, whether or not such algorithms, procedures,
methods or techniques are embodied in a computer program;

                  (ii) any and all programming, marketing, advertising, or
financing strategies, the essential ideas and principles on which such
strategies are based, and any information that might reasonably be expected to
lead to the development of such strategies, conceived, originated, discovered,
developed, evaluated, tested, or employed by the Employee while employed by the
Company, whether or not such strategies are embodied in a computer program;

                  (iii) any and all Internet-related and other products and
services, and the essential ideas and principles underlying such products and
services, conceived, originated, adapted, developed, evaluated, tested, or
applied by the Employee while employed by the Company, whether or not such
products or services are embodied in a computer program, and whether or not
marketed, sold, or provided by the Company;

                  (iv) such information and data pertaining to the business,
operations, personnel, activities, financial status and affairs, current or
anticipated business or investment objectives or practices, current or
anticipated requirements for Internet-related or other products or services, and
other information relating to current or prospective investors, other current or
prospective funding sources, limited partners, shareholders, clients, customers,
accounts, joint venturers, or other business affiliates of the Company, and of
the officers, partners, principals, employees, and other persons affiliated with
such current or prospective investors, limited partners, shareholders, clients,
customers, accounts, joint venturers, or other business affiliates, as is known
to the Employee and as might reasonably be expected to be of value to the
Company in developing, maintaining, or expanding its current or prospective
business relationships with such current or prospective investors, limited
partners, shareholders, clients, customers, accounts, joint venturers, or other
business affiliates.

                                       2
<PAGE>

         (b) PERIOD COVERED; INFORMATION EXCLUDED. The provisions of this
Section 3 shall apply to information acquired by the Employee at any time during
his employment with the Company, whether prior to or subsequent to the execution
of this Agreement.

         The Employee agrees not to disclose to the Company any confidential or
proprietary information belonging to any previous employer of the Employee that
is not affiliated with the Company, or belonging to any other party, without
first securing the written permission of such previous employer or other party.

         (c) DISCLOSURE UPON TERMINATION. Any information required to be
disclosed under this Section 3 that has not yet been disclosed by the Employee
to the Company at the time of the termination of the Employee's employment with
the Company, without regard to when or for what reason, if any, such employment
shall terminate, shall be disclosed to the Company in writing, or in such form
and manner as the Company may reasonably require, within 10 days of the
termination of the Employee's employment with the Company.

         4.  CONFIDENTIAL INFORMATION

         (a) DEFINITION. The parties acknowledge that, in order to permit the
Employee to successfully perform and/or continue to perform the duties
associated with his employment with the Company, it is necessary for the Company
to entrust the Employee with certain valuable proprietary information and
knowledge of certain modes of business operation ("Confidential Information")
which are essential to the profitable operation of the Company, and which give
the Company a competitive advantage over other firms pursuing related business
activities. In the context of this Agreement, the term "Confidential
Information" shall be deemed to include

                  (i) computer software or data of any sort developed (in the
case of software) or compiled (in the case of data) by the Company;

                  (ii) the fact that the Company uses, has used, or has
evaluated for potential use a particular computer program or system, if the
disclosure of such fact to a competitor of the Company might reasonably be
expected to adversely affect the competitive position of the Company relative to
that of such a competitor; provided, however, that information about the type of
computers, computer peripherals, operating systems, database systems, or other
systems software which the Company uses, has used, or has evaluated for
potential use, but which is not specific to any financial or Internet related
application, shall not by reason of this Section 4(a)(ii) be considered
Confidential Information;

                  (iii) algorithms, procedures, methods, or techniques, or the
essential ideas and principles underlying such algorithms, procedures, methods,
or techniques, developed by the Company (but excluding any public domain
algorithm, procedure, or technique), whether or not such algorithms, procedures,
methods, or techniques are embodied in a computer program;

                  (iv) the fact that the Company uses, has used, or has
evaluated for potential use any particular algorithm, procedure, or technique
developed by a party other than the Company, whether or not such algorithm,
procedure, or technique is embodied in a computer program, if the disclosure of
such information to a competitor of the Company might reasonably be expected to
adversely affect the competitive position of the Company relative to that of
such a competitor;

                  (v) the results of any programming, marketing, advertising,
financial, or other analysis conducted by the Company for its own internal use
(and not approved for dissemination to its customers, investors, consultants,
joint venturers, or other parties);

                  (vi) any information that would typically be included in the
Company's income statements, including, but not limited to the amount of the
Company's revenues, expenses, or net income;

                  (vii) any plans for the business of the Company (whether or
not such plans have been reduced to writing); financial information concerning
such plans (including without limitation projected revenues, projected expenses,
projected net income and information concerning rates and costs of customer
acquisition and retention); 



                                       3
<PAGE>

descriptions of such business and technical aspects of or relating to the
operation of such business (including without limitation algorithms, computer
programs, processes or formulas that relate to computer and network security,
authentication, logging, accounting and distribution); and products and services
that the Company is considering offering to its subscribers and/or to other
persons;

                  (viii) any other information gained in the course of the
Employee's employment with the Company that could reasonably be expected to
prove deleterious to the Company if disclosed to third parties, including
without limitation any information that could reasonably be expected to aid a
competitor of the Company in making inferences regarding the nature of the
Company's activities, where such inferences could reasonably be expected to
adversely affect the competitive position of the Company relative to that of
such a competitor;

                  (ix) any other information gained in the course of or incident
to the Employee's employment with the Company that the Company has received from
a third party and is required to hold confidential;

                  (x) any other information gained in the course of or incident
to the Employee's employment with the Company that the Company treats or
designates as Confidential Information and which is not publicly available.

         (b) USE AND DISCLOSURE.

                  (i) The Employee acknowledges that he has acquired and/or will
acquire Confidential Information in the course of or incident to his employment
with the Company. Accordingly, the Employee agrees that he shall not, directly
or indirectly, at any time, during the term of his employment with the Company
or at any time thereafter, and without regard to when or for what reason, if
any, such employment shall terminate, use or cause to be used any such
Confidential Information, whether acquired prior to or subsequent to the
execution of this Agreement, in connection with any activity or business except
the business of the Company, and shall not disclose such Confidential
Information to any individual, partnership, corporation, or other entity unless
such disclosure has been authorized in writing by the Company, or except as may
be required by any applicable law or by order of a court of competent
jurisdiction, a regulatory or self-regulatory body, or a governmental body.

                  (ii) The provisions of Section 4(b)(i) notwithstanding, the
Employee shall be free to disclose any information contained in any material
which the Company routinely makes available to the press and/or the general
public , and shall be free to disclose or use any information which is in or
which enters the public domain prior to the time of such disclosure or use
(except where such information enters the public domain as a result of
unauthorized actions of the Employee). The Employee acknowledges, however, that
(A) a large number of programming techniques and programming strategies, and a
large number of analyses, observations and findings from which such computer
programming techniques and strategies might be derived, have been or may be
reported in the open literature, or may otherwise have entered or may enter the
public domain, and that one of the Company's most valuable forms of Confidential
Information is its accumulated knowledge, based on research, analysis, and
experimentation not reported in the open literature or otherwise falling within
the public domain, of which of these programming techniques, and programming
strategies, and which of these analyses, observations, and findings, are likely
to form the basis for practical, profitable business applications for the
Company ("Confidential Applicability Information"). The Employee thus agrees
that he shall not, directly or indirectly, at any time, during the term of his
employment with the Company, or at any time thereafter, and without regard to
when or for what reason, if any, such employment shall terminate, use or cause
to be used any Confidential Applicability Information in connection with any
activity or business except the business of the Company, and shall not disclose
such Confidential Applicability Information to any individual, partnership,
corporation, or other entity, unless what would otherwise be deemed to
constitute Confidential Applicability Information is itself in or itself enters
the public domain by some means other than as a result of unauthorized actions
of the Employee, or unless such disclosure has been authorized in writing by the
Company, or except as may be required by any applicable law or by order of a
court of competent jurisdiction, a regulatory or self-regulatory body, or a
governmental body.

                  (iii) In the event that the Employee is required to disclose
Confidential Information or Confidential Applicability Information pursuant to
judicial or administrative process or other requirements of law, the Employee
will (A) notify the Company of his receipt of such process within 24 hours of
such receipt, and prior to any disclosure being made, (B) to the extent
reasonably practicable, consult with the Company on the advisability of taking
steps to resist or narrow such request provided that the ultimate decision shall
be that of the Employee, and (C) if disclosure is 



                                       4
<PAGE>

required or deemed advisable, cooperate with the Company in any attempt that it
may make in order to obtain an order or other reliable assurance that
confidential treatment will be accorded to designated portions of such
information. If no such order is obtained by the Company, disclosure of such
information by the Employee shall not be deemed a violation of this Agreement.
If such an order is obtained, then disclosure of the information covered by such
order in the manner described in the order shall not be deemed a violation of
this Agreement. The Employee shall be entitled to reimbursement for his
reasonable expenses, including the fees and expenses of his counsel, in
connection with action taken pursuant to this paragraph.

                  (iv) The provisions of Sections 4(b)(i), 4(b)(ii), and
4(b)(iii) notwithstanding, the Employee shall be free to disclose or use any
information which was obtained by the Employee prior to his employment with the
Company (subject to any obligations owed by the Employee to such previous
employers with respect to such information), or which is obtained by the
Employee subsequent to and independent of his relationship with the Company.

                  (v) The provisions of Section 4(b)(i), 4(b)(ii), and 4(b)(iii)
notwithstanding, the Employee shall, with the prior written permission of the
Company, be free to disclose selected Confidential Information and/or
Confidential Applicability Information to a limited number of parties for the
purpose of securing employment subsequent to the Employee's employment with the
Company or progressing professionally, provided further that where such
disclosure would not be harmful to the Company, such permission shall not be
unreasonably withheld. For purposes of this Section 4(b)(v), the termination of
the Employee's employment with the Company shall not in itself be deemed harmful
to the Company, even if such termination is voluntary.

         (c) RETURN AND OWNERSHIP OF DOCUMENTS AND WORK PRODUCT. Upon the
termination of the Employee's employment with the Company for any reason, the
Employee promises and agrees to return immediately to the Company any and all
Confidential Information and all other materials or documents, including without
limitation mailing lists, rolodexes, computer print-outs, and computer disks and
tapes, belonging to the Company which contain information pertaining to the
Company's business, methods, clients, potential clients, customers, potential
customers, investors, potential investors, funding providers, potential funding
providers, or employees, unless the Company consents in writing to the
Employee's retention thereof.

         (d) OWNERSHIP OF INTELLECTUAL PROPERTY. All right, title, and interest
of every kind and nature whatsoever, whether now known or unknown, in and to any
intellectual property ("Intellectual Property"), including without limitation
any ideas, inventions (whether or not patentable), designs, improvements,
discoveries, innovations, patents, trademarks, service marks, trade dress, trade
names, trade secrets, works of authorship, copyrights, films, audio and video
tapes, other audio and visual works of any kind, scripts, sketches, models,
formulas, tests, analyses, software, firmware, computer processes, computer and
other applications, creations, properties, and any documentation or other
memorialization containing or relating to the foregoing, in each case
discovered, invented, created, written, developed, taped, filmed, furnished,
produced, or disclosed by or to the Employee in the course of rendering services
to the Company shall, as between the parties hereto, be and remain the sole and
exclusive property of the Company for any and all purposes and uses whatsoever,
and the Employee and his successors and assigns shall have no right, title, or
interest of any kind or nature therein or thereto, or in or to any results and
proceeds therefrom. The Company shall have all right, title, and interest in
such Intellectual Property, whether such Intellectual Property is conceived by
the Employee alone or with others and whether conceived during regular working
hours or other hours.

         The Employee makes, and agrees to make and execute, any assignment
necessary to perfect the Company's right, title, and interest in Intellectual
Property, and agrees to perform any act reasonably requested by the Company in
furtherance of any such assignment, and/or of perfecting the Company's rights in
Intellectual Property.

         (e) NO WAIVER OF TRADE SECRET PROTECTION. Nothing contained in this
Agreement shall be deemed to weaken or waive any rights related to the
protection of trade secrets or confidential business information that the
Company may have under common law or any applicable statutes or rules.

                                       5
<PAGE>

         5. COMPETITION WHILE EMPLOYED

         During the period of his employment with the Company, the Employee will
not, directly or indirectly, without the written consent of the Company, and
whether or not for compensation, either for his own account or as an employee,
officer, agent, consultant, director, owner, partner, joint venturer,
shareholder, investor, or in any other capacity :

         (a) perform a function which is of the same nature as, or substantively
similar to, a function that the employee performs for the Company; or

         (b) engage in any activity or business which is the same nature as, or
substantively similar to, an activity or business of the Company or an activity
or business which the Company is developing and of which the Employee has
knowledge.

         6. INTERFERENCE WITH RELATIONSHIPS

         (a) RESTRICTIONS ON INTERFERENCE. While employed by the Company, and
for a period of 18 months after the date the Employee ceases to be employed by
the Company, without regard to when or for what reason, if any, such employment
shall terminate (the "Termination Date"), the Employee shall not, directly or
indirectly, without the written consent of the Company, and whether or not for
compensation, either on his own behalf or as an employee, officer, agent,
consultant, director, owner, partner, joint venturer, shareholder, investor, or
in any other capacity (except in the capacity of an employee or officer of the
Company acting for the benefit of the Company ), knowingly:

                  (i) interfere with an ongoing (as of the Termination Date)
relationship between the Company and one of its customers (except as permitted
under the provisions of Sections 6(b) and 6(c) below) by providing or offering
to provide a product or service to that customer which, as of the Termination
Date, was provided to that customer by a business unit of the Company in which
the Employee worked during his employment with the Company, if by so doing, the
Employee might reasonably be expected to cause the Company to suffer a loss of
profits from or other damage to its business relationship with that customer;

                  (ii) interfere with an ongoing (as of the Termination Date)
joint venture, strategic alliance, licensing agreement, distribution
relationship, advertising relationship, or similar agreement or relationship
between the Company and another business entity (the "Joint Venture
Relationship") by entering into or proposing to enter into a substantially
similar business relationship with that entity, if the Employee was directly
involved in that Joint Venture Relationship during his employment with the
Company, and if by so doing, the Employee might reasonably be expected to cause
the Company to suffer a loss of profits that would otherwise accrue to the
Company in connection with that Joint Venture Relationship, or to suffer other
damage to that Joint Venture Relationship;

                  (iii) employ, or retain as a consultant or contractor, or
cause to be so employed or retained, or enter into a partnership or business
venture with, any person (a "Related Person") who at the time of such action (A)
is an employee of the Company or the D. E. Shaw Group; (B) has been employed by
the Company or the D. E. Shaw Group at any time within the previous 18 months;
(C) is a consultant, sales agent, contract programmer, or other independent
agent who is retained on a full-time or substantially full-time basis by the
Company or the D. E. Shaw Group; or (D) has been retained on a full-time or
substantially full-time basis by the Company or the D. E. Shaw Group as a
consultant, sales agent, contract programmer, or other independent agent at any
time within the previous 18 months; or

                  (iv) solicit, persuade, encourage, or induce any employee of
the Company or the D. E. Shaw Group (or any consultant, sales agent, contract
programmer, or other independent agent who is retained on a full-time or
substantially full-time basis by the Company or the D. E. Shaw Group) to cease
his employment with or retention by the Company or the D. E. Shaw Group.;

                  (v) accept or solicit investment capital or debt financing
(directly or indirectly) from, or accept or solicit employment with, or accept
or solicit a consulting assignment with, any individual or entity, or an
officer, partner, principal, or affiliate of any entity, or another entity
managed by or otherwise affiliated with an officer, 



                                       6
<PAGE>

partner, principal, or affiliate of any entity, that, as of the Termination Date
or at any time within the 18 months immediately preceding the Termination Date,
provided or arranged for the provision of more than 20 percent of the capital of
the Company.

         (b) EXCEPTIONS TO PREVENT UNDUE HARDSHIP. In the event that the
application of Section 6(a)(i) and/or Section 6(a)(ii) would, in the Company's
judgment, cause undue hardship to the Employee, the Company , upon written
request by the Employee, provide to the Employee a written instrument
authorizing such specific exceptions to the provisions of Section 6(a)(i) and/or
Section 6(a)(ii) as the Company shall determine are reasonably necessary to
prevent such undue hardship, the provisions of which instrument shall thereafter
be deemed to supersede the corresponding provisions of Section 6(a)(i) and/or
Section 6(a)(ii).

         (c) PRIOR RELATIONSHIPS. The provisions of Section 6(a)
notwithstanding, the Employee shall not by reason of Section 6(a) be restricted
from resuming, after the termination of his employment with the Company, any
employment or business relationship that preceded his employment with the
Company, or from providing or offering to provide any product or service to a
customer which the Employee provided to that customer at any time prior to his
employment by the Company; provided, however, that Section 4 and the other
provisions of this Section 6 shall continue to apply.

         (d) EXCEPTION FOR UNRELATED ACTIVITIES. The provisions of Section 6(a)
notwithstanding, the Employee shall become free nine months after the
Termination Date to employ, retain, cause to be employed or retained, or enter
into a business relationship with any Related Person provided that neither the
Employee nor any Related Person directly or indirectly engages in business
activities competitive with the business activities of the Company in the course
of such employment, retention, or business relationship.

         (e) NO WAIVER OF COMMON LAW OR STATUTORY PROTECTION. Nothing contained
in this Agreement shall be deemed to weaken or waive any of the Company's rights
or protections that may be accorded by statute or common law as regards the
conduct of the Employee with respect to the Company's business, investors,
customers, clients, joint venture partners, employees, consultants, or
contractors. The Employee authorizes the Company to disclose this Agreement to
any person at any time, including without limitation any employer or prospective
employer of the Employee.

         7. REASONABLENESS OF COVENANTS

         (a) CERTAIN RECOGNITIONS. The Employee acknowledges that the
restrictions specified in Sections 4, 5, and 6 of this Agreement are reasonable
in view of the nature of the business in which the Company is engaged, the
Employee's position with the Company, the previous relationship between the
Company and the D. E. Shaw Group and the Employee's knowledge of the Company's
business.

         The Employee recognizes that the amount of his compensation reflects
his Agreement in Sections 4, 5, and 6, and acknowledges that he will not be
subject to undue hardship by reason of his agreements set forth in Sections 4,
5, and 6.

         (b) MODIFICATION OF RESTRICTION. Notwithstanding anything contained in
Sections 4, 5, or 6 of this Agreement to the contrary, if a court of competent
jurisdiction should hold any restriction specified in Sections 4, 5, or 6 to be
unreasonable, unenforceable, illegal or invalid, then that restriction shall be
limited to the extent necessary to be enforceable, and only to that extent. In
particular, and without limitation on the foregoing, if any provision of
Sections 4, 5, or 6 should be held to be unenforceable as to scope or length of
time or geographical area involved, such provision shall be deemed to be
enforceable as to, and shall be deemed to be amended to cover, the maximum
scope, maximum length of time, or broadest area, as the case may be, which is
then lawful.

         (c) SURVIVAL OF COVENANTS. The obligations of the Employee under
Sections 4 and 6 of this Agreement shall survive the termination of this
Agreement and of his employment with the Company.

                                       7
<PAGE>

         8. REGULATORY COMPLIANCE

         The Employee agrees to abide by all applicable securities laws and all
applicable rules and regulations of the Securities Exchange Commission, the
National Association of Securities Dealers, the Nasdaq National Market , and all
other applicable self-regulatory organizations.

         9.  REMEDIES/ARBITRATION

         (a) INJUNCTIONS, RESTRAINING ORDERS, AND OTHER EQUITABLE RELIEF. The
Employee acknowledges that breach or threatened breach of Sections 4, 5, or 6 of
this Agreement will cause the Company or, as the case may be, the D. E. Shaw
Group irreparable harm for which there is no adequate remedy at law, and as a
result of this, the Company or, as the case may be, the D. E. Shaw Group shall
be entitled to the issuance by a court of competent jurisdiction of an
injunction, restraining order, or other equitable relief in favor of itself,
without the necessity of posting a bond, restraining the Employee from
committing or continuing to commit any such violation. Any right to obtain an
injunction, restraining order, or other equitable relief hereunder shall not be
deemed a waiver of any right to assert any other remedy the Company or, as the
case may be, the D. E. Shaw Group may have at law or in equity. The right of the
Company or, as the case may be, the D. E. Shaw Group to seek equitable relief
under this Agreement shall be in addition to (and not in derogation of) the
requirement imposed on each party hereto to arbitrate disputes as provided in
Section 9(b) below.

         (b) MANDATORY ARBITRATION. The Employee and the Company agree that any
claim, controversy or dispute between the Employee and the Company (including
without limitation its affiliates, officers, employees, representatives, or
agents) arising out of or relating to this Agreement, the employment of the
Employee, the cessation of employment of the Employee, or any matter relating to
the foregoing shall be submitted to and settled by arbitration in a forum of the
American Arbitration Association ("AAA") located in New York County in the State
of New York and conducted in accordance with the National Rules for the
Resolution of Employment Disputes. In such arbitration: (i) each arbitrator
shall agree to treat as confidential evidence and other information presented by
the parties to the same extent as Confidential Information under this Agreement
must be held confidential by the Employee, (ii) the arbitrators shall have no
authority to amend or modify any of the terms of this Agreement, and (iii) the
arbitrators shall have ten business days from the closing statements or
submission of post-hearing briefs by the parties to render their decision. Any
arbitration award shall be final and binding upon the parties, and any court,
state or federal, having jurisdiction may enter a judgment on the award. The
foregoing requirement to arbitrate claims, controversies, and disputes applies
to all claims or demands by the Employee, including without limitation any
rights or claims the Employee may have under the Age Discrimination in
Employment Act of 1967 (which prohibits age discrimination in employment), Title
VII of the Civil Rights Act of 1964 (which prohibits discrimination in
employment based on race, color, national origin, religion, sex, or pregnancy),
the Americans with Disabilities Act of 1991 (which prohibits discrimination in
employment against qualified persons with a disability), the Equal Pay Act
(which prohibits paying men and women unequal pay for equal work) or any other
federal, state, or local laws or regulations pertaining to the Employee's
employment or the termination of the Employee's employment.

         (c) RECOVERY OF LEGAL FEES. If one of the parties to this Agreement
(the "Plaintiff") should bring a proceeding against the other party (the
"Defendant") in connection with an alleged breach or threatened breach of this
Agreement, and if such proceeding is ultimately resolved by an order or a
judgment in favor of the Defendant, by a voluntary discontinuance with prejudice
by the Plaintiff, or by an arbitration decision wholly in favor of the
Defendant, the Plaintiff will, upon presentation by the Defendant of appropriate
evidence of the amount and nature of the expense incurred, reimburse the
Defendant in an amount equal to the lesser of:

                  (i) the cost of all reasonable legal fees actually incurred by
the Defendant in connection with such litigation or arbitration; or

                  (ii) $100,000.

         (d) FORUM. Each party submits to the jurisdiction of the courts, state
and federal, and arbitration forums (set forth in Section 9(b)) located in the
State of New York.

                                       8
<PAGE>

         10. RELATIONSHIP OF THE PARTIES

         The relationship between the Company and the Employee hereunder is
agreed to be solely that of employee and employer. Nothing contained herein and
no modification of responsibility or compensation made hereafter shall be
construed so as to constitute the parties as partners or joint venturers.

         11.  AMENDMENT OR ALTERATION

         No amendment or alteration of the terms of this Agreement shall be
valid unless made in writing and signed by both of the parties hereto.

         12. GOVERNING LAW

         THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE LAWS OF THE STATE OF NEW YORK (WITHOUT REGARD TO CONFLICTS-OF-LAW
PRINCIPLES).

         13. SEVERABILITY

         The holding of any provision of this Agreement to be illegal, invalid,
or unenforceable by a court of competent jurisdiction shall not affect any other
provision of this Agreement, which shall remain in full force and effect.

         14. WAIVER

         The failure of a party to insist upon strict adherence to any term of
this Agreement on any occasion or occasions shall not be considered a waiver
thereof or deprive that party of the right thereafter to insist upon strict
adherence to that term or any other term of this Agreement.

         15. ENTIRE AGREEMENT

         This Agreement contains the entire agreement of the parties and shall
supersede any prior verbal or written agreement or understanding between the
Employee and the Company. The Employee acknowledges that in choosing to accept
the Company's offer of employment (and/or to continue such employment), he has
not relied on any warranties, representations, or promises by the Company, its
employees, or any other parties except as specifically set forth herein.

         16. ASSIGNMENT

         Except as otherwise provided in this paragraph, this Agreement shall
inure to the benefit of and be binding upon the parties hereto and their
respective heirs, representatives, successors, and assigns. Neither this
Agreement nor any right or interest hereunder shall be assignable by the
Employee, his beneficiaries, or legal representatives without the Company's
prior written consent; provided, however, that nothing in this Section 16 shall
preclude the Employee from designating a beneficiary to receive any benefit
payable hereunder upon his death, or the executors, administrators, or other
legal representatives of the Employee or his estate from assigning any rights
hereunder to the person or persons entitled thereunto. This agreement shall be
assignable by the Company to a subsidiary or affiliate of the Company; to any
corporation, partnership, or other entity that may be organized by the Company,
as a separate business unit in connection with the business activities of the
Company; or to any corporation, partnership, or other entity resulting from the
reorganization, merger, or consolidation of the Company with any other
corporation, partnership, or other entity, or any corporation, partnership, or
other entity to or with which all or any portion of the Company's business or
assets may be sold, exchanged, or transferred. With respect to Article VI, the
D. E. Shaw Group is a third-party beneficiary of this Agreement.

                                       9
<PAGE>

         17. NO ATTACHMENT

         Except as required by law, no right to receive payments under this
Agreement shall be subject to anticipation, commutation, alienation, sale,
assignment, encumbrance, charge, pledge, or hypothecation, or to execution,
attachment, levy, or similar process or assignment by operation of law, and any
attempt, voluntary or involuntary, to effect any such action shall be null,
void, and of no effect.

         18. NO COERCION OR DURESS

         The Employee enters into this Agreement with full understanding of the
nature and extent of the restrictive covenants contained herein, and
acknowledges that because of the nature of the Company's business, this
Agreement would not be entered into without the restrictive covenants contained
herein.

         The Employee acknowledges and agrees that he is entering into this
Agreement voluntarily and of his own free will in order to obtain the benefits
of employment, continued employment, and additional compensation by the Company.
The Employee acknowledges and agrees that he has not been coerced or suffered
any duress in order to induce him to enter into this Agreement.

         19. HEADINGS

         The Section headings appearing in this Agreement are used for
convenience of reference only and shall not be considered a part of this
Agreement or in any way modify, amend, or affect the meaning of any of its
provisions.

         20. RULES OF CONSTRUCTION

         Whenever the context so requires, the use of the masculine gender shall
be deemed to include the feminine and vice versa, and the use of the singular
shall be deemed to include the plural and vice versa. That this Agreement was
drafted by the Company shall not be taken into account in interpreting or
construing any provision of this Agreement.

         21. ACKNOWLEDGMENT OF RECEIPT

         By signing below, the Employee acknowledges receiving a copy of this
Agreement.

         22. DEFINITIONS

         For purposes of this Agreement, the term "D. E. Shaw Group" shall
include, individually and/or collectively: (a) D. E. Shaw & Co., L.P. and D. E.
Shaw & Co., Inc.; (b) any partnership, other entity or account that D. E. Shaw &
Co., L.P. or D. E. Shaw & Co., Inc. owns, in whole or in part, or for which they
act, directly or indirectly, as general partner, investment manager, or
management company, along with their respective subsidiaries; and (c) any
predecessor or successor entity to any partnership, entity, or account described
in (b) above. References in this Agreement to any entity also refer to any
successor to that entity.

                                       10
<PAGE>

         IN WITNESS WHEREOF, the parties have executed this Agreement on the
date first written above.



JUNO ONLINE SERVICES, INC.




By:      /s/ David Shaw 
   -------------------------------------
         David E. Shaw
         Chairman of the Board


Date:   4/26/99
     -----------------------------------



EMPLOYEE


Signature:  /s/ Charles Ardai 
          ------------------------------


Name:    Charles Ardai


Address: 1540 Broadway 
        --------------------------------
         New York, NY  10036
        --------------------------------





Date:  4/26/99 
     -----------------------------------

<PAGE>

                                                                Exhibit 10.13(b)

                              EMPLOYMENT AGREEMENT



         AGREEMENT dated as of the 26th day of April, 1999, by and between Juno
Online Services, Inc., a Delaware corporation ("Company"), and Robert H. Cherins
(the "Employee").

         WHEREAS, the Company desires to continue to retain the Employee on the
terms and conditions hereinafter set forth, and the Employee is willing to
continue employment by the Company upon such terms and conditions;

         NOW, THEREFORE, in consideration of the foregoing and in consideration
of their mutual promises and agreements contained herein, the parties hereto
agree as follows:

         1. EMPLOYMENT

         Employment has commenced, and may be terminated by either party at any
time, for any reason, upon 30 days notice (the "Notice Period"), which notice
may be given either verbally or in writing. Notwithstanding the foregoing, the
Company may elect to terminate immediately upon notice, except that in this
event, the compensation and benefits set forth in Section 2 shall be continued
for the duration of the Notice Period. The Employee acknowledges and agrees that
he is an employee at will, and that just as the Employee is free to resign at
any time, the Company has the right to terminate the employment relationship at
any time for any lawful reason. The Employee acknowledges and agrees that no
representative of the Company may verbally change the at will employment
relationship between the Employee and the Company. References to time periods in
this Agreement shall not be construed or interpreted as promising or
guaranteeing employment for any specific duration or until any specific date.

         2. COMPENSATION

         (a) BASE SALARY DURING THE COMPENSATION PERIOD. As compensation for the
Employee's services during the period beginning May 1, 1999 and ending on
December 31, 1999 (the "Compensation Period"), the Company shall pay the
Employee a base salary computed at an annual rate of $150,000 per year, prorated
to correspond to that portion of the Compensation Period during which the
Employee is actually employed with the Company, such base salary to be paid
semi-monthly.

         (b) BASE SALARY AFTER THE COMPENSATION PERIOD. As of the end of the
Compensation Period, or as of the end of any subsequent calendar year, the
Employee's base salary may be increased or decreased, or the manner in which the
Employee is compensated may be changed, in the sole discretion of the Company .
Any such change in compensation shall be deemed to modify only this Section 2 of
this Agreement, and all other provisions of this Agreement shall remain in
effect following such change in compensation. In the absence of any such change,
the Employee's base salary shall remain the same as it was during the
Compensation Period.

         (c) DISCRETIONARY YEAR-END BONUS. The Company may (or may not), in its
sole discretion pay the Employee an additional discretionary year-end bonus. Any
such bonus(es) relating to the Compensation Period shall be paid to the Employee
on a date to be determined by the the Company, which date shall ordinarily be no
later than March 15th of the following calendar year, or as soon thereafter as
is practicable The award and the amount of such bonus shall be determined by the
Company in its sole discretion.

         (d) NON-REFUNDABLE ADVANCE AGAINST BONUS. In addition to the base
salary specified in Section 2(a)the Employee shall, during the Compensation
Period, receive a non-refundable advance against the bonus specified in Section
2(c) computed at an annual rate of $178,500 per year, prorated to correspond to
that portion of the Compensation Period during which the Employee is actually
employed with the Company, such advance to be paid semi-monthly. In the event
that a year-end bonus is paid pursuant to the terms of Section 2(c), the amount
of such advance shall be deducted from such year-end bonus payment. The Employee
shall under no circumstances be required to repay any correctly computed sum
that has already been paid to the Employee as a non-refundable advance against
bonus pursuant to the terms of this Section 2(d).

<PAGE>

         (e) YEAR-END BONUS AFTER THE COMPENSATION PERIOD. As of the end of the
Compensation Period, or as of the end of any subsequent calendar year, the
Employee's year-end bonus, if any, and/or the non refundable advance against
such year-end bonus, if any, may be increased, decreased, or eliminated, or the
manner in which the Employee is compensated may be changed, in the sole
discretion of Company expressed in writing. Subsequent to the Compensation
Period, the Company shall not have any obligation to continue to pay a year-end
bonus or a non-refundable advance against such bonus to the Employee unless such
an arrangement is explicitly agreed to in writing by a duly authorized officer
of the Company.

         (f) STANDARD COMPANY BENEFITS. In addition to the compensation outlined
elsewhere in this Section 2, the Company shall provide to the Employee all of
the benefits included in the Company's standard benefit package, which currently
include medical (hospitalization and major medical), dental, disability, life,
and accidental death and dismemberment insurance. Most of the cost of such
benefits shall be borne by the Company. However, in the case of coverage for the
Employee himself, the Employee contributes a nominal pre-tax amount to the cost
of the medical insurance; if the Employee wishes to obtain coverage for other
qualified family members, and arranges with the Company's insurance providers
(through the Company's Human Resources staff) to obtain such additional
coverage, the Employee will also be required to contribute part of the
incremental cost of such coverage. Individual and dependent medical insurance
contribution amounts are determined on a set scale, based on both the actual
cost of the insurance and on the Employee's base salary. The required
contribution will be borne by the Employee by means of a voluntary salary
reduction in the amount of the contribution implemented by the Company at the
request of the Employee.

         The standard benefit package also currently includes a flexible
spending account plan and a 401(k) retirement plan, available to all qualified
full-time employees after a certain period of employment with the Company. The
401(k) retirement plan currently includes a matching program and a graded
vesting schedule; the Company does not contribute to the flexible spending
account plan, but the Employee may contribute pre-tax dollars. The Employee
agrees that the composition, providers, and all other aspects of the Company's
standard benefit package may be changed from time to time in the sole discretion
of the Management Company.

         (g) EXCLUSIVE COMPENSATION. The compensation and benefits described in
this Section 2 shall be the exclusive compensation due to the Employee from the
Company or any of its affiliates during or on account of the services of the
Employee. If directed by the Company, the Employee shall provide the services
described in this Agreement to one or more affiliates of the Company without
compensation other than as specified in this Section 2.

         3. DISCLOSURE TO THE COMPANY

         (a) DISCLOSURE OF INFORMATION TO THE COMPANY. The Employee shall
promptly disclose and deliver over to the Company, without additional
compensation, to the extent that such disclosure could reasonably be expected to
be of interest to the Company, in writing, or in such form and manner as the
Company may reasonably require:

                  (i) any and all algorithms, procedures, methods or techniques
directly related to electronic communication and/or commerce or to the
Employee's work with the Company, and the essential ideas and principles
underlying such algorithms, procedures, methods or techniques, conceived,
originated, discovered, developed, evaluated, tested, or applied by the Employee
while employed by the Company, whether or not such algorithms, procedures,
methods or techniques are embodied in a computer program;

                  (ii) any and all programming, marketing, advertising, or
financing strategies, the essential ideas and principles on which such
strategies are based, and any information that might reasonably be expected to
lead to the development of such strategies, conceived, originated, discovered,
developed, evaluated, tested, or employed by the Employee while employed by the
Company, whether or not such strategies are embodied in a computer program;

                  (iii) any and all Internet-related and other products and
services, and the essential ideas and principles underlying such products and
services, conceived, originated, adapted, developed, evaluated, tested, or
applied by the Employee while employed by the Company, whether or not such
products or services are embodied in a computer program, and whether or not
marketed, sold, or provided by the Company;

                                       2
<PAGE>

                  (iv) such information and data pertaining to the business,
operations, personnel, activities, financial status and affairs, current or
anticipated business or investment objectives or practices, current or
anticipated requirements for Internet-related or other products or services, and
other information relating to current or prospective investors, other current or
prospective funding sources, limited partners, shareholders, clients, customers,
accounts, joint venturers, or other business affiliates of the Company, and of
the officers, partners, principals, employees, and other persons affiliated with
such current or prospective investors, limited partners, shareholders, clients,
customers, accounts, joint venturers, or other business affiliates, as is known
to the Employee and as might reasonably be expected to be of value to the
Company in developing, maintaining, or expanding its current or prospective
business relationships with such current or prospective investors, limited
partners, shareholders, clients, customers, accounts, joint venturers, or other
business affiliates.

         (b) PERIOD COVERED; INFORMATION EXCLUDED. The provisions of this
Section 3 shall apply to information acquired by the Employee at any time during
his employment with the Company, whether prior to or subsequent to the execution
of this Agreement.

         The Employee agrees not to disclose to the Company any confidential or
proprietary information belonging to any previous employer of the Employee that
is not affiliated with the Company, or belonging to any other party, without
first securing the written permission of such previous employer or other party.

         (c) DISCLOSURE UPON TERMINATION. Any information required to be
disclosed under this Section 3 that has not yet been disclosed by the Employee
to the Company at the time of the termination of the Employee's employment with
the Company, without regard to when or for what reason, if any, such employment
shall terminate, shall be disclosed to the Company in writing, or in such form
and manner as the Company may reasonably require, within 10 days of the
termination of the Employee's employment with the Company.

         4.  CONFIDENTIAL INFORMATION

         (a) DEFINITION. The parties acknowledge that, in order to permit the
Employee to successfully perform and/or continue to perform the duties
associated with his employment with the Company, it is necessary for the Company
to entrust the Employee with certain valuable proprietary information and
knowledge of certain modes of business operation ("Confidential Information")
which are essential to the profitable operation of the Company, and which give
the Company a competitive advantage over other firms pursuing related business
activities. In the context of this Agreement, the term "Confidential
Information" shall be deemed to include

                  (i) computer software or data of any sort developed (in the
case of software) or compiled (in the case of data) by the Company;

                  (ii) the fact that the Company uses, has used, or has
evaluated for potential use a particular computer program or system, if the
disclosure of such fact to a competitor of the Company might reasonably be
expected to adversely affect the competitive position of the Company relative to
that of such a competitor; provided, however, that information about the type of
computers, computer peripherals, operating systems, database systems, or other
systems software which the Company uses, has used, or has evaluated for
potential use, but which is not specific to any financial or Internet related
application, shall not by reason of this Section 4(a)(ii) be considered
Confidential Information;

                  (iii) algorithms, procedures, methods, or techniques, or the
essential ideas and principles underlying such algorithms, procedures, methods,
or techniques, developed by the Company (but excluding any public domain
algorithm, procedure, or technique), whether or not such algorithms, procedures,
methods, or techniques are embodied in a computer program;

                  (iv) the fact that the Company uses, has used, or has
evaluated for potential use any particular algorithm, procedure, or technique
developed by a party other than the Company, whether or not such algorithm,
procedure, or technique is embodied in a computer program, if the disclosure of
such information to a competitor of the Company might reasonably be expected to
adversely affect the competitive position of the Company relative to that of
such a competitor;

                                       3
<PAGE>

                  (v) the results of any programming, marketing, advertising,
financial, or other analysis conducted by the Company for its own internal use
(and not approved for dissemination to its customers, investors, consultants,
joint venturers, or other parties);

                  (vi) any information that would typically be included in the
Company's income statements, including, but not limited to the amount of the
Company's revenues, expenses, or net income;

                  (vii) any plans for the business of the Company (whether or
not such plans have been reduced to writing); financial information concerning
such plans (including without limitation projected revenues, projected expenses,
projected net income and information concerning rates and costs of customer
acquisition and retention); descriptions of such business and technical aspects
of or relating to the operation of such business (including without limitation
algorithms, computer programs, processes or formulas that relate to computer and
network security, authentication, logging, accounting and distribution); and
products and services that the Company is considering offering to its
subscribers and/or to other persons;

                  (viii) any other information gained in the course of the
Employee's employment with the Company that could reasonably be expected to
prove deleterious to the Company if disclosed to third parties, including
without limitation any information that could reasonably be expected to aid a
competitor of the Company in making inferences regarding the nature of the
Company's activities, where such inferences could reasonably be expected to
adversely affect the competitive position of the Company relative to that of
such a competitor;

                  (ix) any other information gained in the course of or incident
to the Employee's employment with the Company that the Company has received from
a third party and is required to hold confidential;
                  (x) any other information gained in the course of or incident
to the Employee's employment with the Company that the Company treats or
designates as Confidential Information and which is not publicly available.

         (b) USE AND DISCLOSURE.

                  (i) The Employee acknowledges that he has acquired and/or will
acquire Confidential Information in the course of or incident to his employment
with the Company. Accordingly, the Employee agrees that he shall not, directly
or indirectly, at any time, during the term of his employment with the Company
or at any time thereafter, and without regard to when or for what reason, if
any, such employment shall terminate, use or cause to be used any such
Confidential Information, whether acquired prior to or subsequent to the
execution of this Agreement, in connection with any activity or business except
the business of the Company, and shall not disclose such Confidential
Information to any individual, partnership, corporation, or other entity unless
such disclosure has been authorized in writing by the Company, or except as may
be required by any applicable law or by order of a court of competent
jurisdiction, a regulatory or self-regulatory body, or a governmental body.

                  (ii) The provisions of Section 4(b)(i) notwithstanding, the
Employee shall be free to disclose any information contained in any material
which the Company routinely makes available to the press and/or the general
public , and shall be free to disclose or use any information which is in or
which enters the public domain prior to the time of such disclosure or use
(except where such information enters the public domain as a result of
unauthorized actions of the Employee). The Employee acknowledges, however, that
(A) a large number of programming techniques and programming strategies, and a
large number of analyses, observations and findings from which such computer
programming techniques and strategies might be derived, have been or may be
reported in the open literature, or may otherwise have entered or may enter the
public domain, and that one of the Company's most valuable forms of Confidential
Information is its accumulated knowledge, based on research, analysis, and
experimentation not reported in the open literature or otherwise falling within
the public domain, of which of these programming techniques, and programming
strategies, and which of these analyses, observations, and findings, are likely
to form the basis for practical, profitable business applications for the
Company ("Confidential Applicability Information"). The Employee thus agrees
that he shall not, directly or indirectly, at any time, during the term of his
employment with the Company, or at any time thereafter, and without regard to
when or for what reason, if any, such employment shall terminate, use or cause
to be used any Confidential Applicability Information in connection with any
activity or business except the business of the Company, and shall not disclose
such Confidential Applicability Information to any individual, partnership,
corporation, or other entity, unless what would otherwise be deemed to

                                       4
<PAGE>

constitute Confidential Applicability Information is itself in or itself enters
the public domain by some means other than as a result of unauthorized actions
of the Employee, or unless such disclosure has been authorized in writing by the
Company, or except as may be required by any applicable law or by order of a
court of competent jurisdiction, a regulatory or self-regulatory body, or a
governmental body.

                  (iii) In the event that the Employee is required to disclose
Confidential Information or Confidential Applicability Information pursuant to
judicial or administrative process or other requirements of law, the Employee
will (A) notify the Company of his receipt of such process within 24 hours of
such receipt, and prior to any disclosure being made, (B) to the extent
reasonably practicable, consult with the Company on the advisability of taking
steps to resist or narrow such request provided that the ultimate decision shall
be that of the Employee, and (C) if disclosure is required or deemed advisable,
cooperate with the Company in any attempt that it may make in order to obtain an
order or other reliable assurance that confidential treatment will be accorded
to designated portions of such information. If no such order is obtained by the
Company, disclosure of such information by the Employee shall not be deemed a
violation of this Agreement. If such an order is obtained, then disclosure of
the information covered by such order in the manner described in the order shall
not be deemed a violation of this Agreement. The Employee shall be entitled to
reimbursement for his reasonable expenses, including the fees and expenses of
his counsel, in connection with action taken pursuant to this paragraph.

                  (iv) The provisions of Sections 4(b)(i), 4(b)(ii), and
4(b)(iii) notwithstanding, the Employee shall be free to disclose or use any
information which was obtained by the Employee prior to his employment with the
Company (subject to any obligations owed by the Employee to such previous
employers with respect to such information), or which is obtained by the
Employee subsequent to and independent of his relationship with the Company.

                  (v) The provisions of Section 4(b)(i), 4(b)(ii), and 4(b)(iii)
notwithstanding, the Employee shall, with the prior written permission of the
Company, be free to disclose selected Confidential Information and/or
Confidential Applicability Information to a limited number of parties for the
purpose of securing employment subsequent to the Employee's employment with the
Company or progressing professionally, provided further that where such
disclosure would not be harmful to the Company, such permission shall not be
unreasonably withheld. For purposes of this Section 4(b)(v), the termination of
the Employee's employment with the Company shall not in itself be deemed harmful
to the Company, even if such termination is voluntary.

         (c) RETURN AND OWNERSHIP OF DOCUMENTS AND WORK PRODUCT. Upon the
termination of the Employee's employment with the Company for any reason, the
Employee promises and agrees to return immediately to the Company any and all
Confidential Information and all other materials or documents, including without
limitation mailing lists, rolodexes, computer print-outs, and computer disks and
tapes, belonging to the Company which contain information pertaining to the
Company's business, methods, clients, potential clients, customers, potential
customers, investors, potential investors, funding providers, potential funding
providers, or employees, unless the Company consents in writing to the
Employee's retention thereof.

         (d) OWNERSHIP OF INTELLECTUAL PROPERTY. All right, title, and interest
of every kind and nature whatsoever, whether now known or unknown, in and to any
intellectual property ("Intellectual Property"), including without limitation
any ideas, inventions (whether or not patentable), designs, improvements,
discoveries, innovations, patents, trademarks, service marks, trade dress, trade
names, trade secrets, works of authorship, copyrights, films, audio and video
tapes, other audio and visual works of any kind, scripts, sketches, models,
formulas, tests, analyses, software, firmware, computer processes, computer and
other applications, creations, properties, and any documentation or other
memorialization containing or relating to the foregoing, in each case
discovered, invented, created, written, developed, taped, filmed, furnished,
produced, or disclosed by or to the Employee in the course of rendering services
to the Company shall, as between the parties hereto, be and remain the sole and
exclusive property of the Company for any and all purposes and uses whatsoever,
and the Employee and his successors and assigns shall have no right, title, or
interest of any kind or nature therein or thereto, or in or to any results and
proceeds therefrom. The Company shall have all right, title, and interest in
such Intellectual Property, whether such Intellectual Property is conceived by
the Employee alone or with others and whether conceived during regular working
hours or other hours.

                                       5
<PAGE>

         The Employee makes, and agrees to make and execute, any assignment
necessary to perfect the Company's right, title, and interest in Intellectual
Property, and agrees to perform any act reasonably requested by the Company in
furtherance of any such assignment, and/or of perfecting the Company's rights in
Intellectual Property.

         (e) NO WAIVER OF TRADE SECRET PROTECTION. Nothing contained in this
Agreement shall be deemed to weaken or waive any rights related to the
protection of trade secrets or confidential business information that the
Company may have under common law or any applicable statutes or rules.

         5. COMPETITION WHILE EMPLOYED

         During the period of his employment with the Company, the Employee will
not, directly or indirectly, without the written consent of the Company, and
whether or not for compensation, either for his own account or as an employee,
officer, agent, consultant, director, owner, partner, joint venturer,
shareholder, investor, or in any other capacity :

         (a) perform a function which is of the same nature as, or substantively
similar to, a function that the employee performs for the Company; or

         (b) engage in any activity or business which is the same nature as, or
substantively similar to, an activity or business of the Company or an activity
or business which the Company is developing and of which the Employee has
knowledge.

         6. INTERFERENCE WITH RELATIONSHIPS

         (a) RESTRICTIONS ON INTERFERENCE. While employed by the Company, and
for a period of 18 months after the date the Employee ceases to be employed by
the Company, without regard to when or for what reason, if any, such employment
shall terminate (the "Termination Date"), the Employee shall not, directly or
indirectly, without the written consent of the Company, and whether or not for
compensation, either on his own behalf or as an employee, officer, agent,
consultant, director, owner, partner, joint venturer, shareholder, investor, or
in any other capacity (except in the capacity of an employee or officer of the
Company acting for the benefit of the Company), knowingly:

                  (i) interfere with an ongoing (as of the Termination Date)
relationship between the Company and one of its customers (except as permitted
under the provisions of Sections 6(b) and 6(c) below) by providing or offering
to provide a product or service to that customer which, as of the Termination
Date, was provided to that customer by a business unit of the Company in which
the Employee worked during his employment with the Company, if by so doing, the
Employee might reasonably be expected to cause the Company to suffer a loss of
profits from or other damage to its business relationship with that customer;

                  (ii) interfere with an ongoing (as of the Termination Date)
joint venture, strategic alliance, licensing agreement, distribution
relationship, advertising relationship, or similar agreement or relationship
between the Company and another business entity (the "Joint Venture
Relationship") by entering into or proposing to enter into a substantially
similar business relationship with that entity, if the Employee was directly
involved in that Joint Venture Relationship during his employment with the
Company, and if by so doing, the Employee might reasonably be expected to cause
the Company to suffer a loss of profits that would otherwise accrue to the
Company in connection with that Joint Venture Relationship, or to suffer other
damage to that Joint Venture Relationship;

                  (iii) employ, or retain as a consultant or contractor, or
cause to be so employed or retained, or enter into a partnership or business
venture with, any person (a "Related Person") who at the time of such action (A)
is an employee of the Company or the D. E. Shaw Group; (B) has been employed by
the Company or the D. E. Shaw Group at any time within the previous 18 months;
(C) is a consultant, sales agent, contract programmer, or other independent
agent who is retained on a full-time or substantially full-time basis by the
Company or the D. E. Shaw Group; or (D) has been retained on a full-time or
substantially full-time basis by the Company or the D. E. Shaw Group as a
consultant, sales agent, contract programmer, or other independent agent at any
time within the previous 18 months;

                                       6
<PAGE>

                  (iv) solicit, persuade, encourage, or induce any employee of
the Company or the D. E. Shaw Group (or any consultant, sales agent, contract
programmer, or other independent agent who is retained on a full-time or
substantially full-time basis by the Company or the D. E. Shaw Group) to cease
his employment with or retention by the Company or the D. E. Shaw Group.; or

                  (v) accept or solicit investmentcapital or debt financing
(directly or indirectly) from, or accept or solicit employment with, or accept
or solicit a consulting assignment with, any individual or entity, or an
officer, partner, principal, or affiliate of any entity, or another entity
managed by or otherwise affiliated with an officer, partner, principal, or
affiliate of any entity, that, as of the Termination Date or at any time within
the 18 months immediately preceding the Termination Date, provided or arranged
for the provision of more than 20 percent of the capital of the Company.

         (b) EXCEPTIONS TO PREVENT UNDUE HARDSHIP. In the event that the
application of Section 6(a)(i) and/or Section 6(a)(ii) would, in the Company's
judgment, cause undue hardship to the Employee, the Company, upon written
request by the Employee, provide to the Employee a written instrument
authorizing such specific exceptions to the provisions of Section 6(a)(i) and/or
Section 6(a)(ii) as the Company shall determine are reasonably necessary to
prevent such undue hardship, the provisions of which instrument shall thereafter
be deemed to supersede the corresponding provisions of Section 6(a)(i) and/or
Section 6(a)(ii).

         (c) PRIOR RELATIONSHIPS. The provisions of Section 6(a)
notwithstanding, the Employee shall not by reason of Section 6(a) be restricted
from resuming, after the termination of his employment with the Company, any
employment or business relationship that preceded his employment with the
Company, or from providing or offering to provide any product or service to a
customer which the Employee provided to that customer at any time prior to his
employment by the Company; provided, however, that Section 4 and the other
provisions of this Section 6 shall continue to apply.

         (d) EXCEPTION FOR UNRELATED ACTIVITIES. The provisions of Section 6(a)
notwithstanding, the Employee shall become free nine months after the
Termination Date to employ, retain, cause to be employed or retained, or enter
into a business relationship with any Related Person provided that neither the
Employee nor any Related Person directly or indirectly engages in business
activities competitive with the business activities of the Company in the course
of such employment, retention, or business relationship.

         (e) NO WAIVER OF COMMON LAW OR STATUTORY PROTECTION. Nothing contained
in this Agreement shall be deemed to weaken or waive any of the Company's rights
or protections that may be accorded by statute or common law as regards the
conduct of the Employee with respect to the Company's business, investors,
customers, clients, joint venture partners, employees, consultants, or
contractors. The Employee authorizes the Company to disclose this Agreement to
any person at any time, including without limitation any employer or prospective
employer of the Employee.

         7. REASONABLENESS OF COVENANTS

         (a) CERTAIN RECOGNITIONS. The Employee acknowledges that the
restrictions specified in Sections 4, 5, and 6 of this Agreement are reasonable
in view of the nature of the business in which the Company is engaged, the
Employee's position with the Company, the previous relationship between the
Company and the D. E. Shaw Group and the Employee's knowledge of the Company's
business.

         The Employee recognizes that the amount of his compensation reflects
his Agreement in Sections 4, 5, and 6, and acknowledges that he will not be
subject to undue hardship by reason of his agreements set forth in Sections 4,
5, and 6.

         (b) MODIFICATION OF RESTRICTION. Notwithstanding anything contained in
Sections 4, 5, or 6 of this Agreement to the contrary, if a court of competent
jurisdiction should hold any restriction specified in Sections 4, 5, or 6 to be
unreasonable, unenforceable, illegal or invalid, then that restriction shall be
limited to the extent necessary to be enforceable, and only to that extent. In
particular, and without limitation on the foregoing, if any provision of
Sections 4, 5, or 6 should be held to be unenforceable as to scope or length of
time or geographical area involved, 



                                       7
<PAGE>

such provision shall be deemed to be enforceable as to, and shall be deemed to
be amended to cover, the maximum scope, maximum length of time, or broadest
area, as the case may be, which is then lawful.

         (c) SURVIVAL OF COVENANTS. The obligations of the Employee under
Sections 4 and 6 of this Agreement shall survive the termination of this
Agreement and of his employment with the Company.

         8. REGULATORY COMPLIANCE

         The Employee agrees to abide by all applicable securities laws and all
applicable rules and regulations of the Securities Exchange Commission, the
National Association of Securities Dealers, the Nasdaq National Market , and all
other applicable self-regulatory organizations.

         9.  REMEDIES/ARBITRATION

         (a) INJUNCTIONS, RESTRAINING ORDERS, AND OTHER EQUITABLE RELIEF. The
Employee acknowledges that breach or threatened breach of Sections 4, 5, or 6 of
this Agreement will cause the Company or, as the case may be, the D. E. Shaw
Group irreparable harm for which there is no adequate remedy at law, and as a
result of this, the D. E. Shaw Group shall be entitled to the issuance by a
court of competent jurisdiction of an injunction, restraining order, or other
equitable relief in favor of itself, without the necessity of posting a bond,
restraining the Employee from committing or continuing to commit any such
violation. Any right to obtain an injunction, restraining order, or other
equitable relief hereunder shall not be deemed a waiver of any right to assert
any other remedy the Company or, as the case may be, the D. E. Shaw Group may
have at law or in equity. The right of the Company or, as the case may be, the
D. E. Shaw Group to seek equitable relief under this Agreement shall be in
addition to (and not in derogation of) the requirement imposed on each party
hereto to arbitrate disputes as provided in Section 9(b) below.

         (b) MANDATORY ARBITRATION. The Employee and the Company agree that any
claim, controversy or dispute between the Employee and the Company (including
without limitation its affiliates, officers, employees, representatives, or
agents) arising out of or relating to this Agreement, the employment of the
Employee, the cessation of employment of the Employee, or any matter relating to
the foregoing shall be submitted to and settled by arbitration in a forum of the
American Arbitration Association ("AAA") located in New York County in the State
of New York and conducted in accordance with the National Rules for the
Resolution of Employment Disputes. In such arbitration: (i) each arbitrator
shall agree to treat as confidential evidence and other information presented by
the parties to the same extent as Confidential Information under this Agreement
must be held confidential by the Employee, (ii) the arbitrators shall have no
authority to amend or modify any of the terms of this Agreement, and (iii) the
arbitrators shall have ten business days from the closing statements or
submission of post-hearing briefs by the parties to render their decision. Any
arbitration award shall be final and binding upon the parties, and any court,
state or federal, having jurisdiction may enter a judgment on the award. The
foregoing requirement to arbitrate claims, controversies, and disputes applies
to all claims or demands by the Employee, including without limitation any
rights or claims the Employee may have under the Age Discrimination in
Employment Act of 1967 (which prohibits age discrimination in employment), Title
VII of the Civil Rights Act of 1964 (which prohibits discrimination in
employment based on race, color, national origin, religion, sex, or pregnancy),
the Americans with Disabilities Act of 1991 (which prohibits discrimination in
employment against qualified persons with a disability), the Equal Pay Act
(which prohibits paying men and women unequal pay for equal work) or any other
federal, state, or local laws or regulations pertaining to the Employee's
employment or the termination of the Employee's employment.

         (c) RECOVERY OF LEGAL FEES. If one of the parties to this Agreement
(the "Plaintiff") should bring a proceeding against the other party (the
"Defendant") in connection with an alleged breach or threatened breach of this
Agreement, and if such proceeding is ultimately resolved by an order or a
judgment in favor of the Defendant, by a voluntary discontinuance with prejudice
by the Plaintiff, or by an arbitration decision wholly in favor of the
Defendant, the Plaintiff will, upon presentation by the Defendant of appropriate
evidence of the amount and nature of the expense incurred, reimburse the
Defendant in an amount equal to the lesser of:

                  (i) the cost of all reasonable legal fees actually incurred by
the Defendant in connection with such litigation or arbitration; or

                                       8
<PAGE>

                  (ii) $100,000.

         (d) FORUM. Each party submits to the jurisdiction of the courts, state
and federal, and arbitration forums (set forth in Section 9(b)) located in the
State of New York.

         10. RELATIONSHIP OF THE PARTIES

         The relationship between the Company and the Employee hereunder is
agreed to be solely that of employee and employer. Nothing contained herein and
no modification of responsibility or compensation made hereafter shall be
construed so as to constitute the parties as partners or joint venturers.

         11.  AMENDMENT OR ALTERATION

         No amendment or alteration of the terms of this Agreement shall be
valid unless made in writing and signed by both of the parties hereto.

         12. GOVERNING LAW

         THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE LAWS OF THE STATE OF NEW YORK (WITHOUT REGARD TO CONFLICTS-OF-LAW
PRINCIPLES).

         13. SEVERABILITY

         The holding of any provision of this Agreement to be illegal, invalid,
or unenforceable by a court of competent jurisdiction shall not affect any other
provision of this Agreement, which shall remain in full force and effect.

         14. WAIVER

         The failure of a party to insist upon strict adherence to any term of
this Agreement on any occasion or occasions shall not be considered a waiver
thereof or deprive that party of the right thereafter to insist upon strict
adherence to that term or any other term of this Agreement.

         15. ENTIRE AGREEMENT

         This Agreement contains the entire agreement of the parties and shall
supersede any prior verbal or written agreement or understanding between the
Employee and the Company. The Employee acknowledges that in choosing to accept
the Company's offer of employment (and/or to continue such employment), he has
not relied on any warranties, representations, or promises by the Company, its
employees, or any other parties except as specifically set forth herein.

         16. ASSIGNMENT

         Except as otherwise provided in this paragraph, this Agreement shall
inure to the benefit of and be binding upon the parties hereto and their
respective heirs, representatives, successors, and assigns. Neither this
Agreement nor any right or interest hereunder shall be assignable by the
Employee, his beneficiaries, or legal representatives without the Company's
prior written consent; provided, however, that nothing in this Section 16 shall
preclude the Employee from designating a beneficiary to receive any benefit
payable hereunder upon his death, or the executors, administrators, or other
legal representatives of the Employee or his estate from assigning any rights
hereunder to the person or persons entitled thereunto. This agreement shall be
assignable by the Company to a subsidiary or affiliate of the Company; to any
corporation, partnership, or other entity that may be organized by the Company,
as a separate business unit in connection with the business activities of the
Company; or to any corporation, partnership, or other entity resulting from the
reorganization, merger, or consolidation of the Company with any other
corporation, partnership, or other entity, or any corporation, partnership, or
other entity to or with which all or any portion of the 




                                       9
<PAGE>

Company's business or assets may be sold, exchanged, or transferred. With
respect to Article VI, the D. E. Shaw Group is a third-party beneficiary of this
Agreement.

         17. NO ATTACHMENT

         Except as required by law, no right to receive payments under this
Agreement shall be subject to anticipation, commutation, alienation, sale,
assignment, encumbrance, charge, pledge, or hypothecation, or to execution,
attachment, levy, or similar process or assignment by operation of law, and any
attempt, voluntary or involuntary, to effect any such action shall be null,
void, and of no effect.

         18. NO COERCION OR DURESS

         The Employee enters into this Agreement with full understanding of the
nature and extent of the restrictive covenants contained herein, and
acknowledges that because of the nature of the Company's business, this
Agreement would not be entered into without the restrictive covenants contained
herein.

         The Employee acknowledges and agrees that he is entering into this
Agreement voluntarily and of his own free will in order to obtain the benefits
of employment, continued employment, and additional compensation by the Company.
The Employee acknowledges and agrees that he has not been coerced or suffered
any duress in order to induce him to enter into this Agreement.

         19. HEADINGS

         The Section headings appearing in this Agreement are used for
convenience of reference only and shall not be considered a part of this
Agreement or in any way modify, amend, or affect the meaning of any of its
provisions.

         20. RULES OF CONSTRUCTION

         Whenever the context so requires, the use of the masculine gender shall
be deemed to include the feminine and vice versa, and the use of the singular
shall be deemed to include the plural and vice versa. That this Agreement was
drafted by the Company shall not be taken into account in interpreting or
construing any provision of this Agreement.

         21. ACKNOWLEDGMENT OF RECEIPT

         By signing below, the Employee acknowledges receiving a copy of this
Agreement.

         22. DEFINITIONS

         For purposes of this Agreement, the term "D. E. Shaw Group" shall
include, individually and/or collectively, (a) D. E. Shaw & Co., L.P. and D. E.
Shaw & Co., Inc. ; (b) any partnership, other entity or account that D. E. Shaw
& Co., L.P. or D. E. Shaw & Co., Inc. owns, in whole or in part, or for which
they act, directly or indirectly, as general partner, investment manager, or
management company, along with their respective subsidiaries; and (c) any
predecessor or successor entity to any partnership, entity, or account described
in (b) above. References in this Agreement to any entity also refer to any
successor to that entity.



                                       10
<PAGE>

         IN WITNESS WHEREOF, the parties have executed this Agreement on the
date first written above.


JUNO ONLINE SERVICES, INC.



By:      /s/ Charles Ardai 
   -------------------------------------
         Charles Ardai
         President


Date:   4/28/99 
     -----------------------------------



EMPLOYEE


Signature: /s/ Robert H. Cherins 
          ------------------------------


Name:    Robert H. Cherins


Address:  1540 Broadway 
        --------------------------------
          New York, NY  10036
        --------------------------------




Date:    4/28/99
     -----------------------------------


                                       11


<PAGE>
                                                                    EXHIBIT 23.2
 
                       CONSENT OF INDEPENDENT ACCOUNTANTS
 
   
    We consent to the inclusion in this Amendment No. 2 to the registration
statement on Form S-1 of our report dated March 4, 1999, on our audits of the
consolidated financial statements of Juno Online Serivces, Inc. (formerly Juno
Online Services, L.P. and Subsidiary) as of December 31, 1997 and 1998 and for
each of the three years in the period ended December 31, 1998. We also consent
to the reference to our firm under the captions "Selected Consolidated Financial
Data" and "Experts."
    
 
/s/ PricewaterhouseCoopers LLP
 
   
New York, New York
May 6, 1999
    


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