I use Facebook to stay in touch with my family and some of my friends - family because they rarely or never use email, and phonecalls can be inconvenient. The good thing about fb-messenger is that we can actually see that the message has been read.
I have three groups of personal friends: some of them, like myself, who keep the laptop/iphone on all day, those who rarely use ...[text shortened]... different groups, they are only 36. Without facebook, communication would be much more complicated.
All but two of my 'friends' on Facebook are family members. (Not all in the UK). I rarely post anything, just good to see everyone is ok and getting on with their lives. (Like Dive, I am shocked by some of the conversations the younger family members have on there, and tend to stay out of those). The 2 main reasons I log in daily to Facebook:
1. Play the quiz game they host with my mum. Other family members played it too at first, but gradually lost interest. - Been playing with my mum every day for over a year. She tends to chose categories like beauty and fashion or films, while I go for art or technology. Great fun.
2. One of my cousins is a talented artist who gets commissioned to paint a lot of celebrities. (Mostly in the world of sport). He often puts pictures of his latest paintings up on Facebook and I like to follow those. (Will happily give his name by PM if anyone wants to google him - Though by 'anyone' I obviously mean someone I trust).