Twitter, Facebook, YouNow, etc. All social media sites will help. I'd recommend Facebook for views as it's easy to share with people liking but if those people will subscribe, I don't know. Then again, I've never been brave enough to post my videos on my personal Facebook page! I don't want family watching, haha.
Twitter is really great I find. JustUnfollow can send out automated DMs with your YouTube channel link if you're into that. Instagram is quite helpful too, to try get people interested in you and stuff.
Just remember, what you put in you'll get out. Spend two minutes on social media sites and you'll get nowhere. You need to connect with people, talk to them and make them interested in you as a person as well as a YouTuber. The more invested they become in you as a person, the more likely they are to invest their time in your videos too.
If you don't tell people about your content, how else are they meant to know it exists?
