I am about to start using shoping engines to promote my products. (EX: Nextag, Shopping.com, Shopzilla, PriceGrabber) The purpose of using these sites is obviously to increase sales directly through the sites. All of these sites are very high authority. All of the above sites are PR 5 and above (PriceGrabber is PR7). When I add my products to thoes sites I will get a link to my product page. My question is will these links have any affect on my SEO/google rankings?