make sure that the website you are using to promote your content has your friends on it. why? because they are the ones who like and retweet your content and then their subscribers check their work and see your work.
for me, I probably got only like 3 views from twitter and no subs from there. things do take time, try to tweet more often and try to ask your followers questions so that they reply to you and you get a conversation going and soon someone will sub.
your personal facebook is your friend, your friends will deffinatly watch your content, I know some of my friends of facebook do that. but u have to be a good facebooker to your friends and don't spam them, just post the video as your status and on your wall.