Iv been posting as a responce, maxing the crap out of my tags, spam posting the link to every website I can think of (where promotion posts are appropriate of course, but Im sure people on facebook are getting annoyed with me lol) like for some examples, livejounal, tumblr, facebook, twitter, reddit, ect.
Comment lots on other peoples videos, interact with the community.
Try and get my friends to share my video around ("Have you posted my video to your facebook yet?! WHY ON EARTH NOT D:<")
BUT, I think the biggest thing thats really been working for me is timing my videos so I post a video on a topic that people are going to be looking for. For example, I posted a video on a controversy issue that the Brony community was buzzing about and got a buttload of views. I posted a video about something going on in an anime show right as soon as it happened. Im planning on coordinating my reviews of things like the animated Hobbit when the next movie trailer for the upcomming Hobbit comes out. Coordinating and timing have been whats got me the most views so far. My videos that were about animes that werent current barely got any views at all. So I think timing is the biggest thing.