Margin on an item is different than gross operating margin. Amazon makes 20%+ margin, "pretty healthy", on "a lot of what it sells" (almost all retail items th

Margin on an item is different than gross operating margin. Amazon makes 20%+ margin, "pretty healthy", on "a lot of what it sells" (almost all retail items that are marked down 30% or less from their MSRP) and .5% isn't a lot of that. It is less than Amazon loses on popular books, and less than they lose on prime shipping. Of all the things Amazon loses money on to incentivize customers, it's a small one. Gross operating margin is only tangentially related and can be increased by them at any time by spending less money on other investments.