I think OP means Amazon’s discount on AWS. Many customers on AWS have contracts that guarantee discounted rates given sufficient volume. People have commented

I think OP means Amazon’s discount on AWS. Many customers on AWS have contracts that guarantee discounted rates given sufficient volume. People have commented on hn about negotiating them, and you can see some examples from recent IPO filings. Amazon (the non-AWS parts) are yet another customer of AWS, and wherever possible you should expect them to operate like one. They even buy RIs!