Thanks for the kind words about the site everyone!
Yes Stas is right, advertisers pay you to show ads on apps, just like anywhere else on the web

What he didn't mention is that he runs one of these networks

They are called Zohark ads and we've heard a lot of good things about them, although we haven't run them ourselves. We tend to run CPM ads or our own CPA offers on our apps, as far as I know Zohark does PPC for publishers.
Anyways, back to the topic... there are also a thousand other ways to monetize an app, basically the sky (or your creativity) is the limit. You can get users to complete CPA offers in exchange for points or items, run traditional PPC/CPM ads, sell advertising, etc.. I know people with extremely simple and stupid (yet active) quiz apps that have made
thousands and thousands of dollars just by placing a PPC ad where the submit button "should" be. (they actually placed it under the ad, but since the ads used to look like the submit buttons, users would click the ads) Of course, you don't have to be sneaky to earn money (and Stas probably doesn't appreciate it

), but the point I'm trying to make is that there are an infinite amount of earning strategies when it comes to FB apps.
also, sorry for the dashes in the url. appsrus.com was taken

haha
take care everyone, and let me know if you have questions or are interested in an app, either custom or turnkey

you can probably reach us at
appsrus@live.com the quickest.
take care everyone!