Streaming
Because social media is a conversation, it's easy to start writing as if everyone "out there" is actually "in here" – right in your brain, following along with your train of thought. Or, if they're not right "in here," surely they've been reading all of your conversations as they've unfolded – haven't they?
Of course that's not the case, and it can make your stream-of-consciousness updates pretty indecipherable to someone who is just discovering you on a social network.
Your social network profile page (and everywhere else you display your updates, e.g., a Twitter feed on your blog or website) may be someone's very first impression of you. What will they find there?
Spewing
Twitter has gotten a pretty bad rap from people who say they have no interest in hearing what their friends or colleagues ate for breakfast. And that's understandable when some people spew out overly personal updates or drawn-out private conversations.
As with everything else, balance is the key.
Warning: Indulging in this two-headed social media writing sin can made your reader feel excluded and disconnected.