Amazon is basically reducing the 30 day free return shipping on apparel to 7 days, in return for a 10% discount if you keep 3 items or more.
It does not seem to include 3p sellers as it only available on ~1 million items. This will hurt 3p sellers, time will only tell us how badly.
Can't wait to see the Prime Wardrobe splitting threads to save the 20% or the popular filler items.
Buy a $200 coat, add 4 cheap items to save $40.