I'm a member of lots of big social media/networking sites, but I only use a few. Here is how I use them:
- Facebook - I used to only use Facebook to let people find me. I basically created my profile so people from the past could find me and send me a friend request. Then I'd usually send them an email, catch up, and just forget about it. Lately I've been using it marginally more, reading it when I'm really, really bored, and posting to it occasionally (although mostly I just share my Twitter updates with Facebook when I think it's appropriate for that audience). I'm not even remotely selective here - I can't think of a single request I've turned down besides people named things like Spammy McNotYourFriend.
- LinkedIn - I use LinkedIn sort of like I used to use Facebook, but work-specific. I accept virtually every request I get, I'll respond to direct messages, and I'll look up people's contact information if I need it, but that is just about it. It's a nice way to keep tabs on my network without actually trying to keep up with them. I never read anyone's posts on there, although I sometimes do share tweets with it.
- Google Buzz - This is the only thing Google ever did that I don't absolutely love. Oh, that and the Android platform, which I'm not behind at all. But those are the only two things. This whole thing is just a poorly-executed waste of time. I will say I always get a little tickle when I happen to bump into someone in there.
- SAP Community Network and ASUG.com (login required) - These are strictly work areas. I blog in both spots, and occasionally turn up in the forums, but mostly I use these sites to gather information to make me more perfectly adequate at my job.
- Twitter - My true online love. Sure I'll occasionally tweet about what I ate for breakfast, and read when others do the same, but I like Twitter because I have a lot of friends on there with similar work interests, so I can talk somewhat randomly about life and work and not have to worry about a filter between the two. I like that you have to be clever and concise. I like that you sometimes speak in a sort of secret code that people that aren't in Twitter don't understand. And I like the conversation, which is totally cliché and totally true. Twitter is the one place where I'm selective about who I follow (but not who can follow me) because I simply don't have time to really follow more than 100 people (and I'm up to about 250).
I like social media because it allows me to stay in touch when I don't have time to stay in touch. I can drop out for a few weeks and its not a huge deal. I can participate in the middle of the night whether other people are online and actively participate or not. I can more easily segregate my friends into non-work, work, or both, and I can choose when to interact with each.
And it makes sure I never miss things like VanDerMemes (via @gweiswasser).