I like the idea of Google+. Constant feeds about topics you're interested in. I like Google Hangout so that's the main reason why have a Google+ account. Other than that, I can care less. I hate it that Google suggests people I don't even know to be part of my circles, and they show up all the time. How do I disable that?
I also have a Facebook and Twitter account. I only signed up on Facebook because I'm a developer. I don't post on Facebook unless it's to showoff a new expensive tech toy I just got. I don't send friend requests, but will accept friend requests from people I know. I also hide myself from the public. Fuck Facebook!
Twitter never really caught my eye. I can careless what people are thinking. I don't need to know what they are doing every hour of they day.
Call me old fashion, but I'm just not into Social Media. If it doesn't die soon, I'll have no choice but to join in all the fun someday because rumor has it, that in the future, your internet profile will be considered when you're applying for a job.