I forget but I believe Amazon gets a decent chunk of its earnings from AWS too.
The number of times I have ordered an item and recieved texts confirming both that the item was unavailable and recently delivered is extremely high. It almost always goes "thank you for your order" "we do not have any X but will replace it with X.1" "we can't deliver your order" "your order has been delivered" with no interaction from me other than to accept replacements when I placed the order.
Walmart interface also just sucks.