Top 15 ad networks, March 2008

Audience, 000 % Reach
Total Internet 188,010
Platform-A 170,537 90.7
Yahoo! Network 160,336 85.3
Google Ad Network 152,048 80.9
Specific Media 145,554 77.4
ValueClick Networks 140,091 74.5
Tribal Fusion 135,640 72.1
Casale Media Network 129,399 68.8
DRIVEpm 124,333 66.1
adconion media group 117,469 62.5
interCLICK 108,818 57.9
Traffic Marketplace 105,420 56.1
Collective Media 100,151 53.3
24/7 Real Media 94,525 50.3
ADSDAQ by ContextWeb 94,459 50.2
Burst Media 93,291 49.6
Source: comScore