someone bought a book from me on Amazon with expedited shipping. They happen to live very close so Media mail and Priority mail will arrive the same day. The difference in price is big. When I go to Amazon to confirm shipment, I have to enter the shipping company and shipping method. so it would be USPS media mail or USPS priority. 1) Would Amazon care if the buyer paid for expedited shipping and I enter USPS media mail in Amazon? 2) Can the buyer leave me bad feedback for shipping by media mail? How do I tell the buyer "hey, you stupid idiot, it would have arrived the same day"?