Back in grad school (oh how old I feel at this moment), we ran through a case study on WalMart. The principle they were extolling was the Just In Time method of delivering product to shelves. It seems that WalMart is so good at controlling their ordering, and has so much power over their suppliers, that they don't pay for goods until they sell them.
Think about that for a second.
WalMart has food in their grocery that they promise to pay the grocer for just as soon as someone buys it from them. There is no other retailer in the country that gets to have inventory on their shelf that they don't own, outside of a consignment shop. That's how much power they have. They can force Nabisco, PepsiCo and Coca-cola to give them inventory for free, to hold until it's sold. And if it doesn't sell? They just send it back. That's insane.
And that's what Amazon seems to be aspiring to. This is why I shop at my little retailers whenever I can. We buy meat, veggies and fruit from local farms and try to patronize non-chain stores whenever possible. The loss of the little corner shops just makes me angry. Those places have way more specialized information and incentive than you can get at the big chains. Now I just have to figure out exactly what to do with my Amazon Prime membership.