Facebook has its uses, the main use being that so many people are on it. I managed to make contact with my step brother that I hadn't seen since I was ten years old. I'm not a lover of talking on the telephone, so it gave me the confidence to go ahead without the fear of rejection. We chatted and sent messages for a while, and found out that we only live 30 miles apart. It was amazing when we all met up. He logs onto facebook nearly every day now, as he hadn't used it for months before finding my message.
Also use it to talk to OH's relative in America, Australia and New Zealand, and to play silly addictive games. It's each to their own, I've tried twitter a few times, but it's not for me.