but having the label have the ability to push your tracks also helps.

both. when i see a track on a label i like, i at least listen to it. the reputation of the label push your track. also, if it is a great track, the label do the active promotion (which you may not be able to afford) is great. they want to make the most money on your track which means getting it out to the most people possible. it works both ways.
for example, when i started spinning house, i sent a few tracks to some friends and said, who should i look at to find stuff like this. they responded by sending me some artists, and several labels. when a label is known for having quality tracks, everyone knows that it is going to be quality, even if it isnt their style.

inversely, if someone really doesnt like a label (there are a few disco house labels i really dont like) people know that and are less likely to check it out. i check them out every no and again to see if they are doing something good for a change, but never on a regular basis.