I've had the same thought as well. Showing products that may be related to the product customers are looking at could be a good way to upsell. It sure would be nice if there were a referral system too. As an example "Oh you are looking at our Dev Boards... well you may be interested in femtocows Pogo Pin ICSP Adapter as well." What could happen here is we could design our dev board to fit the pogo pins so that it makes sense for the customer to buy both at the same time. Kick us back a tiny ad fee if the sale is made because we recommended the product. Win Win for Everyone!