These two sites get a lot of traffic because they both have great rankings in the Google search engine. Google looks at the title of the article or video, so the key to using these sites is having good keywords in the title. I wrote about finding traffic generating keywords in this previous post (second section of the post), so check that out if you don’t have experience with keyword research.
To drive traffic back to your blog, EzineArticles lets you have a link to your blog at the end of each article. And with YouTube, you should display your blog URL at the beginning and end of your videos. Also, you can leave a link back to your blog in the description of each video.