Amazon already had free shipping and returns before for Prime users. This however is a completely different psychology to online shopping.
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> This however is a completely different psychology to online shopping.
“Buy more and get a discount which increases, within some range, based on quantiry” is not new in any area of retail, including online shopping.
What amazon is doing is not the same as this quote. This isn't buying in bulk. This is more kin to B&M retail shopping where you don't have to pay any upfront costs to try on an article of clothing and assess fit. Only now, it's in the comfort of your own home.
The discount would be icing on the cake, but in the realm of fashion, 10-20% off is game changer.
Quantity-based discounts of 10-20% at volumes of 3-5 items are low in clothing retail; 25% at a quantity of two isn't uncommon (consistency and simplicity across the board of the Amazon discount structure might be somewhat novel, but the level of discount is not.)
No upfront costs is isomorphic to “buy on credit with low-friction returns”.