I have yet to sign up.

I have missed meetups, other social engagements, family photo shares, news and such that were on FB only. Get routinely made fun of by family and friends since I am the "techy" who is "afraid" of technology as they say.

But people I care about I contact via email, chat, talk in person or phone. Maybe I am strange and I just never felt the need to either broadcast to everyone what I am doing or keep an eye on what everyone else is doing unless I am talking to them one one one.