As filed pursuant to Rule 424(b)(3)
Registration No. 333-78959
Prospectus Supplement dated December 6, 1999
to Prospectus dated August 18, 1999
DOUBLECLICK INC.
$250,000,000 4.75% Convertible Subordinated Notes due 2006
(Interest Payable March 15 and September 15)
--------------------
3,030,303 Shares of Common Stock
--------------------
The information contained in the table appearing under the heading
"Selling Securityholders" on pages 40 - 42 of the Prospectus is hereby amended
to add the following information:
<TABLE>
<CAPTION>
Principal Shares of
Amount Common
of Notes Percentage Stock
that May of Notes that May
Name of Selling Securityholder be Sold Outstanding be Sold
- --------------------------------------------------------------------------------------------------
<S> <C> <C> <C>
Alta Partners Holdings, LDC.................................... $5,030,000 2.0% 60,969
Amoco Corporation Master Trust................................. 962,000 * 11,660
Greyhound Lines................................................ 100,000 * 1,212
Hotel Union and Hotel Industry of Hawaii....................... 407,000 * 4,933
ITG Inc........................................................ 117,000 * 1,418
Jeffries and Company Inc....................................... 9,000 * 109
Pepperdine University Pool A#1................................. 71,000 * 860
PGEP IV, LLC................................................... 88,000 * 1,066
Tracor, Inc. Employees Retirement Plan......................... 143,000 * 1,733
Viacom Pension Plan Master Trust............................... 53,000 * 642
</TABLE>
- ------------------------------
* less than one percent
The information contained in the table appearing under the heading
"Selling Securityholders" on pages 40 - 42 of the Prospectus with respect to the
Selling Securityholders named below is hereby deleted and restated with the
following information:
<TABLE>
<CAPTION>
Principal Shares of
Amount Common
of Notes Percentage Stock
that May of Notes that May
Name of Selling Securityholder be Sold Outstanding be Sold
- --------------------------------------------------------------------------------------------------
<S> <C> <C> <C>
Salomon Smith Barney Inc....................................... $1,687,000 *% 20,448
</TABLE>
- ------------------------------
* less than one percent
