We've pointed out more than a few times how digital goods muck up traditional markets that are based on the concept of scarcity, and it appears that eBay has come to the same conclusion. It's now banned the direct sale of purely digital goods from either its auctions or its direct sales offerings. Instead, those who want to sell digital goods need to put up a classified ad on the site, rather than a transactional platform. The basic reason has to do with the (wouldn't you know it?) infinitely reproduceable nature of digital goods. That allows eBay sellers to list the same product many, many, many times over, since they have an infinite supply. This practice is screwing up listings and (more importantly) is being used to manipulate feedback ratings, and so eBay has done away with it.