If you try this out, please share how it works out. I remember interning there I had access to very cheap shipping (~30% FedEx/UPS rates). This seems like a neat way to get access to the same benefit.
Mostly joking, so someone else will need to try it out. :) My guess is that if it worked well enough for people to start abusing it, they'd close the loophole. As another poster points out, you still need to pay their transaction fee, so the shipping savings has to more than offset that in order for the trick to even be worthwhile.
