Facebook led all online publishers in the first quarter of 2011 with 346 billion display ad impressions, representing 31.2 percent market share, according to the comScore data released Wednesday.
Facebook’s market share has increased 15 percentage points from 16.2 percent in Q1 2010. Yahoo! Sites ranked second during the most recent quarter with 112 billion impressions (10.1 percent), followed by Microsoft Sites with 54 billion impressions (4.8 percent) and AOL with 33 billion impressions (3.0 percent).
Overall, nearly 1.11 trillion display ads were delivered to U.S. Internet users during the quarter.
AT&T ranked as the top online display advertiser in the first quarter with 19.5 billion impressions, accounting for 1.8 percent of display ads. Experian Interactive ranked second with 16.6 billion impressions (1.5 percent), followed by Scottrade, which ranked third with 11.2 billion (1.0 percent) and Intuit with 11 billion (1.0 percent).
Groupon entered the top 10 display advertisers at No. 7 with 7.7 billion impressions (0.7 percent).