Facebook is pretty much only useful as a place to spy on your ex or get random hookups from girls you knew 5 years ago.
I will bet you anything that the average occurrence of reconnecting with some hot chick you used to have a crush on in high school but didn't talk to much, and then meeting up at a bar and getting wasted together and you bang the bejeezus out of her, then not talking again for like a month and it never goes anywhere, has increased by like 15,000% since the launch of Facebook. That's probably worth $50.