Just curious as this is something I may be interested in, but what exactly comes along the lines of creating a facebook app? Is their any expenses towards it outside of the price for the designer, how would the back office look for the app, ect. Any information will be welcomed as I am totally clueless in this area.
read http://www.facebook.com/apps/application.php?id=6265023907 complete guideline for How To Build A Facebook Application
I can sell you some facebook apps to get you started. pm me if you want. Ill give them to you cheap 10-20 bucks.
Skid: All you have as a backend cost is hosting; Facebook also gives users the ability to send you questions, but in my experience, nobody uses this feature anyway. khaled111: You can try the usual... affiliate programs and banner advertising. If you're creating a game, you can also sell special items.