Internet ads generated $31 billion in 2011 NEW YORK, April 18 (UPI) -- Internet advertising revenue soared in 2011, hitting $31 billion, a trade group based in New York reported Wednesday. The Internet Advertising Bureau said revenues for ads rose 22 percent over 2010, putting revenues at a record high two years running. The report on the industry was prepared by accounting firm PricewaterhouseCoopers. The report also says the fourth quarter of 2011 produced $9 billion in advertising revenues on the Internet, a record for a three-month span. For the quarter, revenues jumped 15 percent over the third quarter's take. The fastest growth segment in the digital landscape was mobile advertising, which rose by 149 percent to $1.6 billion in 2011 from revenues of $600 million in 2010. The report said display-related advertising brought in $11.1 billion in revenues, 35 percent of the total. Retailers maintained their spot at the top of the list of industries using the Internet to spread the word about their wares. Retailers spent $7.1 billion on Internet ads in 2011, 22 percent of the total, up from 21 percent and $5.5 billion in 2010.