Popular social networking site Facebook.com led all online publishers in Q1 2011 with 346 billion display ad impressions, representing 31.2 percent market share. 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, Inc. with 33 billion impressions (3.0 percent).

☛ comScore – Press Release: “Facebook Ranks as Top Display Ad Publisher in Q1 2011”, May 4th, 2011

comScore, Inc., a leader in measuring the digital world, today released an overview of the U.S. online display advertising market for Q1 2011 based on data from comScore Ad Metrix, indicating that nearly 1.11 trillion display ads were delivered to U.S. Internet users during the quarter. Facebook accounted for 346 billion impressions, nearly double the number it delivered in Q1 2010, and accounting for nearly one third of all display ad impressions delivered.
“The U.S. online display advertising market maintained its strong momentum from last year with a terrific first quarter,” said Jeff Hackett, comScore executive vice president. “We are now seeing more than one trillion display ads delivered every single quarter and nearly 300 individual advertisers spending at least $1 million a quarter on display, numbers which underscore just how large and vibrant the online medium has become. And it’s not just about the volume but about the quality of the advertising experience that can be delivered as we see continued investment in compelling, high-quality creative that helps cultivate long-term brand equity.”