There is a common misconception that, if you practice SEO, you need to get on forums so that you can create links (usually in the signature line that shows below each post) because SEO is all about link building. The truth is that in terms of link building those shown on forums have a very small significance but they can have a much greater value in another way.
ECommerce and Reviews, Reviews, Reviews
With Google displaying reviews in an ever more prominent way both in Google shopping and in its’ organic search results this is obviously becoming an increasingly important factor in SEO. It’s not so much that good reviews effect your rankings directly (although this can be true in Google Shopping and Google+ Local) but that some nice yellow stars attract internet users to click through to your site.