VideoEgg
This means players watch an ad before being allowed to play a game for free. It does require them to be patient, but it also works as they are a captive audience. You can get plenty of advertising inventory from companies including Game Jacket, Mochi Media, VideoEgg, and Ultramercial, and it's a very easy way to make revenues with your game. Be aware, however, that developers now get a pretty small amount of revenues from advertising this way (unless they have major traffic). But developers can also use these adverts to drive micro-transaction sales, selling a special 30-day item that turns off the advertising. That item can make you a lot more money per player than the advertising would have. You can also offer "optional" advertising, rewarding players that turn on the adverts with virtual coins or experience boosts. A new trick is to offer "invisible" wrappers, so if a game is played on your Web site, there's no advertising, but if someone grabs the game and puts it on their site (30,000 sites do this), then advertising before the game turns on automatically. So they got your game, but you get their advertising.