The Onion has an ad that you see every time you go to the site, while you’re being redirected to the main page. They’ve been running free for years, and have recently added streaming videos. Of course, they’re strictly a humor site and not a game, but the point is that you should be able to charge more for ads that are more prominently displayed.

I’m not a marketing person or anything, so I could be way off. But I still think more ads are a good way to make revenue. People who play browser games generally log on at least once a day. That’s a lot of traffic.