Sometime ago I delete my facebook account. One of the primary reasons was the time wasted on it that could be better spent doing something productive. I was adding no value to my life by using it.
I deleted my Facebook account just a few weeks ago, along with my Google account. I don't like feeling dependence.
My Google account is still gone — turns out it wasn't giving me much value besides the email, and I hated my Gmail name so not much loss there. But I restored Facebook within 24 hours. I have too many people that I can't talk to in any other way. While I enjoyed the freedom, I enjoyed the friends much more.
So I restored my account, but deleted every friend I thought to be nonessential. I wound up with nine friends, each of whom I'm constantly in some state of conversation with. So I can't waste time as easily — I don't write notes as much, I'm rarely tagged in photos by them — but I'm still able to use it to talk.
That's what I love about Facebook's design. It's granular. You can choose to barely use it at all and it still gives you some value.