Well, I went on Facebook about 5 years ago, because of work. My boss told me to make an app interact with FB. I didn't tell anyone about it, yet some friends found me there. Since then, I've added some friends, removed some friends, tried to keep the friends list small. It's now at about 40 people.
I think it's ok. We have there a group for our weekly video evening, where people comment the last films we watched, ask whether it takes place next week or not, say what movies they like or not and so on. And else... I Have maybe 20 new posts per day of my friends, which are about all kinds of stuff about their life, which I can ignore or not. So I don't care.
I don't need it, but I don't mind using it.