Apparently fresh content helps with SEO according to these articles:
4 Ways to Keep Your Website Fresh & Get Tons of Traffic from Google
http://smallerbox.net/blog/ecommerce/keep-site-content-fresh-and-get-tons-of-traffic-from-google/Freshness Factor: 10 Illustrations on How Fresh Content Can Influence Rankings
http://www.seomoz.org/blog/google-fresh-factorSo blogging and updating with new products really does help! What do you do to keep your content fresh?