I am seeing a facebook developer which already have an app that pages can add in to see who are their top fans on their page and engage/comunicate with them.
Basically the fan who comment/like the most.
Thing like awards and bonus will be a plus. Historical data all good to have as well.
You should have the source code and provide a demo url .
If selected i may request that you integrate it with an existing system.
Do not bid if you not have a viewable demo link available.