Create more youtube videos and get people to subscribe to it, when you have a lot of subscriber , you can create another video where you can talk more about your product or your site or whatever you want to promote. Since you have those subscriber and they will aware of it. Another way getting more traffic like others mention on this post doing SEO (rank your site in search engine) or you can do other stuff: PPC, Buy targeting ads at buysellads, doing Press Release and distributed using PRWEB, social media (FB, Twitter, Linkin).
If i were you, Do Not depend on SEO only. Diversify always the best!