Gain an audience. Building an audience is key to increasing your monetization. You need people to watch your ads in order to make any money off of them. There is no one secret to getting more subscribers, just make the best content that you can and they will come to you.
Keep uploading content and try to get people hooked. Send your video out on Twitter and Facebook. Share it with people. Distribute it elsewhere on the internet. Subscribers are essential to becoming a partner.
Interact with your viewers by responding to comments and making occasional videos directly related to viewer comments and questions. Connecting with your community will bring more members into that community.