what do you think are ebay's weaknesses?
jmount: I think most of the features are irrelevant- you need to find some way to break the "network effect" (large number of buyers attract sellers, large number of sellers attract buyers) like Craigslist did.A cautionary point is your idea also has to something that is not true for Amazon (else Amazon would have already crushed eBay).  From what I have seen a big blocker is the rigidity of Amazon's catalogue versus eBays.  For example an eBay seller selling obscure components to repair fishing reels doesn't need variable pricing and would be happier using Amazon for the payments (versus PayPall)- but has no idea how you would enter these unique items into Amazon.