That's not necessarily true. Amazon may provide cheaper distribution/shipping thereby reducing the end-user price even though the supplier is paid the same. A

That's not necessarily true. Amazon may provide cheaper distribution/shipping thereby reducing the end-user price even though the supplier is paid the same. Amazon is also increasing the overall reach of each supplier thereby increasing demand and sales volume. It also opens up new arbitrage opportunities. For some people, the convenience of Amazon is worth paying a higher price for certain items. Due to those consumers, sellers like this can make substantial profit: https://www.youtube.com/watch?v=vzrtdUCsYTQ https://www.youtube.com/watch?v=vzrtdUCsYTQ The behavior shown in the video is a great example of the 'pie' actually expanding. The arbitrage seller is creating demand at Walmart and other local businesses, Amazon is making some profit, and the end-buyer is also better off since they gained the convenience which they likely value > the original price + arbitrage margin.