I adore social media. I have enjoyed it for many years now but each network of people I communicate with has its own pros and cons. I tailor my online behaviour to accomodate these differences. For example my LJ (the home of this blog) is perfect for longer musings, for watching the communities that interest me, and reading the scant few blogs that are posted here by current friends/acquaintances. Twitter is of course tailored for 140 character replies, retweets, postings of short comments, and links. Facebook is more useful for sharing personal information, along with some photos and links and whatnot.
But it's the people on these sites that realistically determine what I want to broadcast via that medium. On Twitter, I'm more brief and varied. On Facebook I avoid posting statuses about politics and religion (though I might reply to someone else's post or like it if appropriate). I post more photos to Facebook. I might complain more via Twitter (though I do try to keep complaining to a minimum online regardless). I might also post more about food via Twitter (as it is where more food people I know congregate)!
My willingness to post about more varied things on Twitter provides the opportunity to engage in completely different types of conversation than Facebook and vice-versa. Same goes for my blog, and all the other social media sites I frequent. My online identity on each is slightly different as well. And you know what, while this is always changing just a bit, I like it this way.