WHY?
I reactivated my Facebook. My social life didn't suffer too much from the deactivation, I thought it would suffer a lot more than it did. I reactivated it because I have to admit it's pretty useful. It's easy to have a conversation from phone to computer, it's easy to schedule events, and more people use it. I deactivated it because I felt almost addicted to the notifications (I know, right?) but I think the ~3 month break fixed that up.
