I've used Amazon for years for the sheer convenience, and recently was the first time I ever needed to return anything (12 video cards that required more power than our machines could provide). The return process was about as simple as they could make it, find the order, click return, provide a reason, done. What was interesting - if a little strange - was that it mentioned UPS pickup but didn't provide a way to print a label. I actually went through the wizard a second time thinking I had missed something. Gave up, figured either something would happen or I'd follow up in a few days. A couple days later I got a recorded call explaining that UPS would be coming for the box with a pre-printed label on day x. Easy enough.
Worked out just that way too, though it was the first time my UPS guy had seen the return handled that way as well. So maybe was just me that it was mildly confusing, but it worked just fine and required very little effort to get done.