But... it instantly lost all appeal once my parents and grandparents joined. I used it for a bit to keep up with friends after college, but then I decided I would de-friend anyone I hadn't actually spoken with in the last year... or didn't expect to ever really talk with again in the future. I did that every year for a few years... and eventually just shut down my account. For me, noise exceeded signal. Every time I got an alert it was some fake friend wanting to connect or share something I didn't care about.
I keep in touch with friends I care about with text messages, and we have our own Slack channels... and that's good. The absolute last thing any of us want is this super-public, broadcasted-bullshit, boast-fest full of people we don't really care about. Some girl I thought was cute when I was in college... there's no reason I need to know when she has kids or what she is up to 15 years later... superficial friendships are just a time sink that take away from real friendships.
Anyway yeah, 5+ years Facebook-free and no regrets on that. I like Snapchat (saying this as a nearly-40-year-old) because, like natural conversation, it's not some crapy thing that comes back to haunt you. Say what you want, and it's gone. (But... yeah, I HATE that it's stored on some server somewhere for the government or advertisers to use to track me.)
Slack groups work really well for me and a few of my groups of friends. Because we know they are exclusive, and won't spam us, we actually value them. When someone has a message for the entire group... "I got engaged / married / had a kid / new job / moving to Singapore..." whatever... it's just information, not someone trying to milk fake internet points from strangers.
Focus on real friends, focus on communication that mimics real life... you say things... and they're gone. Imagine if some asshole was walking around with a tape recorder and recording every conversation you had... that's how I see Facebook / Google+... The whole concept of these networks just makes me cringe.