I've got a lot of experience with this as I've developed some large scale affiliate data feed tools that runs on many sites.
Basically, the dupe content isn't helping you. This isn't the same thing as stealing the content from another site where there might be one or two other sites with the same content. You're using product descriptions that hundreds or even thousands of other sites are using. And Google does have it's methods of detecting the original source of content, not that it's always accurate but it does attempt to determine who the real owner is.
What you need to do is add unique content to your site and try to rank those pages, not the product pages made up of dupe content pulled from your feed.
Some sites do this by creating category description pages where they create a good 600-700 word intro to the category, place it high on the page within an jQuery slider or something so it doesn't eat up all the page's real estate.
Another option is to add custom content articles then either include relevant product info from your feed in that page or link to relevant product pages. These articles could be general buyers guides like "How to pick the best coffee table for your home". Create a whole series of guides and even articles on the latest news or offerings that relate to the types of products your site sells.
You could also add the ability for users of your site to leave ratings, comments or other user submitted content to product pages that would dilute the duplicate content.
Basically, Google declared war on data feed sites a long time ago, discounting them as spam. You need unique content.
And as with any site, more, quality back links always helps. But get the back links to your category pages and articles. You can try to get a bunch of back links to product pages made up of dupe content but it's only going to work if you can "out back link" all the other sites using the same data feed.
In the long run, that's not the best option. Adding good, unique content to your site not only convinces Google to rank you better, creates link bait but gives your visitors a better impression of your site. It's not just about getting traffic, you still have to convince that traffic to covert into sales.