Bombarded by ads when you visit your favorite websites? A new study released by comScore says more than 1 trillion display ads were received by Americans in the first quarter of 2010. That’s a 15 percent increase from a year ago.

So, which site is the leading publisher of display ads? Yahoo? Google? Those make the top 10 list, but the top honor (or dishonor if you hate those ads) goes to Facebook.

From comScore:

Popular social networking site Facebook.com led all online publishers during Q1 with 176 billion display ad impressions, representing 16.2 percent market share. Yahoo! Sites ranked second with 132 billion impressions (12.1 percent).

You can find out the other sites that led the U.S. in display ad impressions below.

Top 10 U.S. Online Display Ad Publishers Q1 2010
(Total U.S. – Home/Work/University Locations; Source: comScore Ad Metrix)

1. Facebook.com

2. Yahoo! Sites

3. Microsoft Sites

4. Fox Interactive Media

5. AOL LLC

6. Google Sites

7. Turner Network

8. Glam Media

9. eBay

10. Tagged.com

The ads measured don’t include video ads, house ads, or ads smaller than 2,500 pixels. But they do include things like banner ads.

Display ad spending reached about $2.7 billion, according to the study. As for the top online display advertiser in the first quarter – that’s AT&T, with 26.3 million ads served, which is 2.4 percent of the market. Verizon follows with 21.8 million ads served and 2 percent of the market share. Scottrade, Inc., Experian Interactive and Sprint Nextel Corporation round out the top 5.

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