Guys, why do you do this...?

It's hard to say exactly, but think about it....why would you only stay in contact w/ certain people and not others? I think alot of it has to do with how much of a connection that you have with this person. ie: similar views, similar things in common, etc. Maybe that person knows exactly what to say at the right time. It really doesn't have alot to do with keeping them on a "backburner". Also the girls maturity level during the breakup can really set the tone for future contact!!!! (I'm sure it's the same for you ladies...am I right??)