Minor nitpick, Apple has always taken a 30% cut of in-app purchases. Amazon never used in-app purchases for transactions, I believe they used to have some sort

Minor nitpick, Apple has always taken a 30% cut of in-app purchases. Amazon never used in-app purchases for transactions, I believe they used to have some sort of in-app WebView that let users buy books on the amazon.com website. Apple told them they needed to either give them a 30% cut of those sales, or remove the WebView.