bhartzer - 6:36 pm on Mar 27, 2012 (gmt 0)
I have generally found that product descriptions that are about 50-75 words long are "light on content" and could use more words to describe them.
You may want to start a blog or a section of the site that feature certain products, and has extensive information about them. Could be a blog, with more photos, video(s), reviews, etc.. Certainly your more profitable or best-selling products might be ones to focus on first.
You do have related products, and that will continue to help--but user reviews could be added, as well.
The next step would be to start working on more deep links to your products and category pages, links from other sites. Social bookmarks and using other social sites such as Pinterst come to mind.