They do. And it's one of those "I have all the money so you'll do whatever I tell you to do and I'll pay you whatever I want, OR ELSE" deals. Amazon pays the USPS $1 to deliver all packages! You heard me. 20 lbs from CA to NY? $1! They may take it part of the way, but USPS delivers it for $1. Here's the kicker. IF it doesn't get there on time, they pay nothing. Yet these assclowns can't hold themselves to their own standards! So (and yes I know exactly what I'm talking about, and have to listen to it EVERY SINGLE DAY) so IF these freakin' Amazon clowns get to the local PO 3 hours after they are due, and 3 hours after the carriers have gone out, (which is a routine at every local post office I know about!) the local PO has two options. One, call the carriers back from miles away to pick up their 5-10 or 50 amazon packages, even if they have already done the part of the route those packages to and even if that means driving 20 miles out of the way with no pay for it. Option 2 is to send them out the next day and not get paid. They are all delivery scanned with GPS locator scanners. If your "Prime" delivery gets there at 8:00 in the morning on day 3, USPS did it for free. And the ONLY reason they are late is because the Amazon drivers don't get the packages to the PO on time, literally 3-4 days every business week in the case of my wifes office.
Option 3---I'll guarantee you my wife has put 10K miles on her new truck delivering these packages and SHE IS THE FREAKIN POSTMASTER! Not a mail carrier. But it's "Deliver them or else" from the USPS management who is so afraid of losing their business that they have also gotten onboard with the Amazon philosophy of not caring about their employees at all while they promise this unattainable service level goal before it's logistically possible.
Let me clarify: My wife gets written up every time an amazon package doesn't make it on time. And even if she easily documents that "the amazon truck got here at 10:00 today, two hours after my carriers were out on the routes" even though that truck was due at the PO by 7:00, it doesn't matter to USPS or to Amazon. Amazon doesn't pay so USPS writes them up. Even better, Amazon write USPS up as an "on time delivery failure" even though it was THEIR FAULT!
Amazon is the FREAKIN devil and some day, we'll all be sorry we patronized them. MARK MY WORDS!