WackWall is a free service with some cheap premium features. We also want to support the project with ads to cover running expenses.
One big thing is that we don't want to jeopardize user experience. No stupid animated banners are welcome. Context targeting doesn't work, that's the reason why we didn't just tastelessly throw Adsense units around. There must be something deeper otherwise it's not going to work with social networking sites.
If you know of an ad company that has more effective targeting approach than anything else on the market let us know.