I have some youtube videos I want to promote that promote my site. Would it be smart to treat them the same way as I do my main site and get backlinks towards them doing web 2.0 and having them links inside the articles or doing social bookmarking and blog commenting with the youtube video links in it. Or is it smarter just to do backlinks to my main site? Thanks for your advice
Yea, why not? If you can get more than one site (a youtube video and an article) ranking in Google, you will get more traffic.