Dan Martell's Flowtown got shut down because Facebook didn't like the fact that they were selling private data of users (I got this from http://www.youtube.com/watch?v=a7eLPcSJIog).
I've built www.whiqq.com which lets people search publicly available posts from Facebook fan pages only. But what people or businesses actually want to search is public posts from people's profile to generate leads and not just the Fan pages. I know Facebook policy does not allow that and it does not allow to build search engine using Facebook data. But companies like www.buzznumbershq.com and http://www.brandwatch.com/ are doing this.
- Should I build it anyway ? Because I know I can do a better job and provide better analytics!!
- Should I not work on a product that requires me to search with Facebook data ?
- Why are companies like buzznumbershq and brandwatch still indexing Facebook data ?
I would avoid anything to do with Facebook at this point. The network is consumed with spam and low level engagement. Have an app? Google Apps or Apple are the way to go.