Revealing numbers for Amazon
According to this Wall Street Journal story (subscription required):
Sales related to third-party merchants, or retailers who sell through Amazon's site, have been an increasing part of Amazon's business for a couple of years. The company, which charges merchants a commission on their sales and, in some cases, "rent" for selling on its site, says it needs merchants to help it offer the broadest selection of products possible. Amazon said 28% of its unit sales in the second quarter came from independent merchants, up from 24% a year ago.
It'll be interesting to see how eBay's entry into this space with its ProStores offering impacts Amazon's numbers in a few quarters.