to be honest, I listen to comps a lot and I'm more likely to discover new artists through comps than through artist releases. most people who say they don't listen to comps really don't listen to much chipmusic anyway.
this advice is more to everyone than to the OP: if you are going to do a comp, do it right. people are going to put effort into their contributions, under the impression that you are actually going to deliver on your end. if you never end up releasing it, that's going to hurt your reputation, especially if you are a newbie. but more than that, some comps are plagued by not getting enough submissions, whether it's because a lot of artists drop out by the deadline, or because there was never enough interest to begin with. don't think that putting together a successful comp is easy, and don't do it just to promote yourself.