To purchase Kindle books, you can select the device or app you want the book sent to in the deliver to: drop-down. Amazon Ads enable your books to appear in prominent placements in the Amazon store, helping you capture readers' attention while they're browsing for books.Once you've completed the checkout on Amazon's side, you'll get a thank you notice. In that thank you notice, choose "Manage Your Content and Devices." If you haven't done these steps yet, go to the Home screen now, select Set Up Your Kindle, and follow the onscreen prompts. When I log into my account, using the exact same URL, the option to purchase Kindle books just disappears. You may be in the time period where they are reviewing your book, which can take up to 72 hours. Amazon states quite clearly that you cannot turn off 1Click ordering for Kindle books. It's very intentional. If you bought your Kindle online using your Amazon account, it is already registered to you.