If you’ve ever opened the Kindle app on your iPad and searched fruitlessly for a "Buy" button, you aren't alone. Because of Apple’s policy of taking a 30% cut of in-app digital sales, Amazon doesn’t allow direct book purchases within either the Kindle for iOS app or the standard Amazon shopping app.
To successfully purchase a book, you must bypass the apps and use your iPad's web browser (like Safari or Chrome).
: Tap Buy Now or Buy now with 1-Click . You may see a "Deliver to" dropdown menu; select your iPad if it appears, though the book will sync to your entire library regardless.