I deleted facebook about six months ago because it was a huge stressor that added very little value to my life. I have too many subsets of friends, which makes it impossible to maintain one personality without offending someone. This just isn't how human's interact and I think it will eventually kill off facebook, unless they find some way to mitigate it.

For reference: 1) Highschool friends and family who are incredibly religious/right wing/etc 2) Friends from skiing, many of whom make a living on the mountain, who are about as vile as one can imagine 3) Friends from college or work, which consists mostly of PharmD's, MD's, and nurses. 4) Other random friends from startup stuff, partys, etc