I use Twitter in a very different way than Facebook though, and for very different reasons. I follow a small group of smart, funny or creative people that tweet really interesting stuff, but personally I tweet only a few times a month. Am I alone in that I don't use Twitter as a social networking tool, and more of a broadcasting-listening tool?
To anyone looking at my twitter, it might seem extremely quiet and ghost-townish, but I am using Twitter much more than Facebook and getting more from it, albeit passively.
Twitter is, for me, very much a "right now" tool. I used to read up on missed posts, but now I just follow too many people. So I look at the recent history of a couple of lists, then look at even less of my main stream for interesting conversations/links.
FB/G+ feel far more involved, even if I'm doing the same thing. I chalk this up to the conversations being longer, and more in depth/nuanced.
To anyone looking at my twitter, it might seem extremely quiet and ghost-townish, but I am using Twitter much more than Facebook and getting more from it, albeit passively.