For years, retailers have given preferential shelf space to certain products — sometimes because they are higher margin, or because the manufacturer has paid for that placement. Should be any different? During the holiday season, the online retailer listed its Kindle e-reader at the very top in search results for "sony reader." Clever! Even better, a search for "kindle" doesn't mention its Sony competitor at all. My personal favorite? A number of customers have tagged the Kindle with "sony reader." That's what loser-generated content gives you, I guess.