Why would I want to post other peoples articles when I have so much content already – my product descriptions, sale pages and reviews? These are the key pages that I want indexed high in the search engines too.
First off, you need to stand out from your competitors, and having some interesting, relevant content besides your product information can make your site more engaging for your customers. In addition, content that is not just about your products can help you establish some authority in your product niche. Not only do your customers see that you are keeping up with the relevant news, trends and ideas. The search engines also like to see this broader content.