Most of the SKUs they ordered are no longer eligible for prime delivery. This was several years ago.
The only other time this has happened for me was with some wine glasses; one out of the four in the package (single stock unit) was broken and they said I should keep the item. I guess in general they're not interested in receiving broken glass returns.
Whether it's glass or not, as soon as it's not resellable as the original product it becomes worse than worthless. There is no sane way for them to deal with a SKU of "3 glasses", total quantity: 1.
I ordered some batteries for portable two-way radios. Some of them arrived completely dead (zero volts; high impedance at the charging terminals) and sure enough they want them back even after I indicate they're bad.
...amazon warehouse on the other hand worked no questions asked despite questionable economics
2) bed bugs
Mattresses are big. They stand out when left on the side of the road.
I'm guessing that me shipping that watch from Finland to the UK would've cost way too much.
I did have to ship in a broken Seagate HDD back to Amazon.de on their dime though, so it's not just them not wanting broken goods back. Although that might also be Seagate wanting it back for warranty purposes even though I went through Amazon?
What would be sneaky would be for UPS to sell Amazon things that look to the customer like a return label, but they just throw it in the trash without shipping it ...
That's the most important part of it. If people could figure out and trigger it intentionally, the whole model would break.