Honestly I have not really found a place yet to use for channel promoting that is not bogged down with others just spam posting their content. Some people say joining a community for your niche helps. While it is fun to join the niche and talk to people with the same interest as you, I do not think it helps you get immediate views unless you shove your content down that communities throat. No one likes having content shoved down their throat.
This site is pretty good to put your videos on though. You do have to unlock the video forums first with your ytcash stuff but i think it is worth it. I have also started using twitter a decent amount and putting hashtags and things on my tweets and that seems to help.