"I'm going to be very clear right now," Stolar said. "Google is involved in in-game advertising. I'm going to say it one more time, in case there's any misconceptions here: in-game advertising. This is an area that Google believes will have tremendous growth over the next number of years. ..."

That means game publishers will be able to use the Google system to put advertising in their games, and advertisers will be able to work through the Google system to buy ad space within games. Schaffer said it will start with ads in Web-based games, with plans to move into PC and console games later on.