In my opinion, it's an amazing achievement that Amazon has with the AWS cloud service and Amazon store. First, Amazon created a store that had the need for a huge infrastructure of machines to support it. In addition to moving from books to selling everything, Amazon then began to sell computing power. Depending on how you look at it, and I choose a simplistic way, the Amazon store infrastructure is running on an AWS and is essentially free. I don't know the accounting numbers of course, but companies are purchasing AWS cloud services and indirectly paying for the Amazon store compute infrastructure. The Amazon store additionally benefits beyond just economics by having a more robust and functional cloud infrastructure because developers like us demand it for AWS. It’s really unique.
eBay, Google, Microsoft, and others don’t have this synergy. eBay’s backend has to be funded entirely by the percentages it takes on transactions in their store. Microsoft has to compete with its cloud service without the benefit of an internal huge user (store) that helps fund it. Google's backend cloud is somewhat funded and shared by the search engine. But it’s indirect funding vs the more direct Amazon store system.
I find Amazon store-AWS almost beautiful in its symbiotic nature with each other. When Amazon released Amazon Echo, its backend ran on an AWS of course. Echo also added additional ways of buying more products from the Amazon store. The Amazon Echo cost for production could eventually be written off as a storefront. Amazon could sell the Echo for a loss but make it up by selling products either physically or eventually virtual ones to the Alexa skills.
So with the Amazon store, AWS, and Amazon Echo products, you have a powerful triad all supporting each other. The fact that Alexa can also be on other non-Amazon devices and not burden Amazon with production costs propels their store further. I’m not sure how Google, Microsoft or eBay can compete as efficiently.
Thing of beauty