I like facebook. It's great to keep up with people I don't get to see especially as I moved from the South to the North of the UK. However I keep my numbers small, I don't add anyone I don't know and review my friends regularly. I never add people I haven't met and even newbies I have met get deleted I we then don't communicate on fb. If people don't comment on my stuff, or they don't post themselves, then there is no point us being connected. It's about putting some effort in.
I did 'delete' my twitter however as I found I had no interest in the day to day lives of people I don't know. Plus everyone on twitter has FANTASTIC lives and can make you feel like you're a bit third wheel. I don't get tagged on rubbish with fb but did on twitter I kept my twitter but deleted all my followers. I keep the account to follow things like the ISS or if there are specific things I may want to search from but I don't tweet from it.
I'm on fb/twitter etc., twitter I tend to dip in and out of, but I have been a member for years, I follow a few interesting celebrities and the rest are real people, some I have met in real life and some I have hobbies in common with. Facebook is similar, but harder to dip in and out of.