Google claimed the number-one spot in U.S. display advertising in the first quarter, with 14.7% of the market ($396 million), up from 13.3% in Q4 2010. Yahoo's hold on the market declined from 13.6% to 12.3%, or $330 million, in that same period. Facebook, meanwhile, had 8.8% of the display market, or $238 million. Karsten Weide, IDC vice president and the author of the report, says he expects Fac