Internet ad revenues hit $7.9 billion for the first six months of 2006--a record 37 percent gain over the first half of 2005, according to data released by the Internet Advertising Bureau and PricewaterhouseCoopers. Online ad revenues crossed the $4 billion mark during the second quarter. Paid search again accounted for the biggest chunk of online ad revenues at 40 percent--the same as in the year-earlier period. Display ads, including rich media and banner ads, increased the most--by 3 percent to 31 percent of revenues. CPMs also continued to be the main pricing model online, representing 48 percent of ad buys. Performance-based deals, however, dropped to 40 percent from 47 percent, while hybrid models gained favor, growing to 12 percent from 5 percent.