my guess is that UPS will eat their lunch. this is UPS's core business. they prob weren't doing what Amazon needed them to do partially because they have other customers and partially because Amazon likely wanted too much from them based on what Amazon was willing to pay. Amazon will likely place onerous requirements on sellers to squeeze pennies out of the shipping process. and then, eventually, when more of commerce has converted to the mail-delivered model, and UPS is making a profit, and Amazon realizes that they're throwing good resources after bad in an experiment gone wrong, they'll get back to focusing on selling stuff and out of the business of delivering stuff.