Nothing, Amazon offers you no protection unless you use their Buy Shipping, which is just normal carriers, nothing different from what we all use. But somehow UPS, USPS, FedEx, are just magically covered through Amazon.

Why do they do this?

Amazon most likely has NET terms for paying carrier balances. They more than likely take that money and sit on it making interest.

So, if they collected 5 billion in Buy Shipping per month, they're probably pulling in around 200 million annually in a high yield account. I have no idea how much they sell.

Amazon makes money selling you labels. Their rates are very good. Their contractual agreement might be across the board including FBM, FBA and Amazon product shipments or they may have separated 3rd party FBM buy shipping from the FBA, Amazon product shipments.

All I can tell you is all the shipping software companies, the mainstream ones, all have the same rates. Even Amazon matches up to those rates. All of them make money off each label sold. So Amazon, no matter what is making money off you using their services.

Think of Amazon as the mob. You pay the mob for protection. You have no other option, but to pay the mob or lose money. It's a modern-day shakedown. Everything Amazon does, is to benefit Amazon's bottom line, profit. Profit is a good thing for a company, yes, but Amazon also has the ability to help sellers defend themselves against non-receipt claims. They choose not to, so you choose Buy Shipping.

We all know this is an issue. We all know buyers know this is an issue. We all know a large percentage of A-Z claims of "Package didn't arrive" are scammers and they received their product. Porch theft and non-delivery/lost packages isn't that high. How do we know this? We compare this to other sales avenues. Amazon is higher than every other sales avenue we have put together. That's saying something. And it's a percentage-based calculation, to account for volume.