Re: Barely use them.
My Facebook account is so old that when I got it you had to have an email address at one of two UK universities to sign up. I keep it only because there are two people whom I cannot contact any other way, and since I hardly ever contact them it will probably go soon.
In the UK, though, Facebook has a huge demographic problem, because none of da kidz use it and it has all the coolness of something your parents and gran like. See also: the BBC.