There was a lot of talk about him being a good moderate candidate, but he didn't seem to get much attention. He could've kept going and done decently, but it'd have been a lot of time, effort and money lost just for some small chance at being offered the VP slot and some increased name recognition nationwide... so understandable that he doesn't think it worth it.

Perry seems to have the momentum on his side, we'll see if that lasts... last time around certainly showed us the frontrunners in the pre-election year aren't necessarily doing that well by the time Super Tuesday has come and gone.

Edit: Super Tuesday, of course, not Sunday... though I'm still not sure why it is on a Tuesday.