• by Gavin O'Malley  @mp_gavin, May 13, 2010

U.S. Internet users received a record 1.1 trillion display ads during the first quarter of the year, marking a 15% increase year-over-year, according to new data from comScore. Overall, U.S. display ad spending in the first quarter reached an estimated $2.7 billion, with the average cost per thousand impressions equal to $2.48.

"Following a severe ad recession that began in late 2008 and continued through the first three quarters of 2009, we've been seeing a strong resurgence in the online display ad market," said Jeff Hackett, comScore senior vice president.

"The first quarter of 2010 posted strong volume in online display ads, coinciding with increasing expenditure from advertisers and higher CPMs for publishers," Hackett added. "This pickup in activity should bode well for the online advertising industry as we move forward in 2010."

Beating Yahoo for the first time, Facebook led all online publishers during the first quarter with 176 billion display ad impressions, which represented a 16.2% market share. Yahoo sites ranked second with 132 billion impressions -- 12.1% -- followed by Microsoft Sites with 60 billion impressions -- 5.5% -- and Fox Interactive Media with 53 billion impressions -- 4.9%.

While Facebook's showing is certainly impressive, it should be noted that both Yahoo and Microsoft operate huge display ad networks, which translates to significantly higher earned revenue. For that reason, Facebook has long been rumored to be considering the launch of its own ad network.

AT&T, meanwhile, led competitor Verizon as the top online display advertiser in the first quarter with 26.3 billion impressions, accounting for 2.4% of all display ads. Verizon held the second position with 21.9 billion -- 2% -- followed by Scottrade with 16.4 billion -- 1.5% -- Experian Interactive with 15.6 billion -- 1.4% -- and Sprint Nextel Corporation with 10.1 billion -- 0.9%.

For the purposes of comScore research, display ads include static and rich media ads, but exclude video ads, "house ads" and "very small ads," or those smaller than 2,500 pixels in dimension.

Separately, the Interactive Advertising Bureau and PricewaterhouseCoopers said Thursday that online ad revenue for the first quarter grew 7.5% year-over-year, reaching $5.9 billion. That number actually represented a drop from the fourth quarter of 2009, when ad revenue reached $6.26 billion.