>If you return unopened wine to Costco, for example, they throw it out

The food and groceries I already knew about. However, Amazon throwing out returned clothes was a surprise because I've seen clothing retailers like Macy's just put the returned items right back on the rack for re-sale. When you go to a shore store, they don't throw out every pair of shoes that customers tried on and didn't buy. So I just thought Amazon just did the same thing at their warehouse. I've also returned car wax to an OReilly's Auto store and I watched the clerk just put the bottle right back on the shelf for the next customer to buy.

It was disconcerting to find out I was adding to the landfill just because I returned clothes to Amazon. Nowadays, I don't order clothes from them unless I'm 100% sure I won't be returning it.