Next step is to making your video "viral," a term that means a video has become so popular that people are sending it to their friends and its popularity is uncontrollable.
Promote your videos on social network websites like MySpace and Facebook, etc. Make a personal video blog and post your videos and promote them. Add to video search engines. Brand your channel by create a attractive logo and channel theme settings. Include a link to your YouTube account in all of your emails.
Find out which of your YouTube videos are doing well using Google Analytics and YouTube Insight and copy what made them successful. Make some research about popular videos, keywords, comments, subscriptions etc. and make appropriate changes to popularize.