Either everyone is keeping this wonderful source of traffic close to their chests or people are ignoring this wonderful source of traffic?
Which one is it? With the holiday season upon us, I think it's time to liven this place up. If you sell products and are not utilizing Google's product search to sell your products, you are missing out on a very nice source of traffic that converts extremely well.
Actually my two largest competitors, both of whom are very active in SEM & SEO, seem completely oblivious to Product Search. That space seems to be dominated by the Internet-only players, who are getting destroyed by big offline brands at every other turn. They've either assessed it and dismissed it as being more trouble than its worth, or have absolutely no idea it exists.