iPad & iPhone not allowing kindle app book purchases

You should be able to buy it by logging into your Amazon account from any web browser. I do that all the time. Are you saying that's not working for you? What is happening when you try?

Yes, for Kindle books, this is indeed the case.

As perverse and non-sensical as it may seem, Amazon require you to purchase Kindle books either from a Kindle device - or by using the Kindle Books webpage on the Amazon website. Once purchased, books can be downloaded from your Kindle Library to your Kindle App.

https://www.amazon.com/gp/help/customer/display.html%3FnodeId%3DGDZF9S2BRW5NWJCW

Amazon have deliberately contrived their Kindle App to allow download of purchased books - but will not allow you to purchase books directly from the Kindle App. Amazon likely have a commercial interest in forcing you to purchase books in this manner (perhaps in encouraging you to purchase a Kindle Reader) - and only they have the ability to change App functionality.

Any representation that you wish to make needs to be directed to Amazon. One day, if enough customers complain, perhaps Amazon will change their current policy 🙂

The reason is really simple though. Amazon refuses to pay the Apple 30% fee in-app purchase fee, just as they won’t pay the Google Play store fee on Android. They claim that with both store’s fees, and the requirement on price parity in-app with their own online store prices makes selling books in-app unprofitable.

Same thing with Barnes and Noble Nook app, which has a tab for “bookstore” but you cannot actually purchase any books there. You have to open a browser and go to B&N online then download in app. Google Play Books and other ebook apps with online stores are the same.

You must make the purchase from Amazon on the web. Then open the kindle app and sync your library to sync that new item to the device app.

See -> https://www.amazon.com/gp/help/customer/display.html%3FnodeId%3DGDZF9S2BRW5NWJCW

Michael Black wrote:

The reason is really simple though. Amazon refuses to pay the Apple 30% fee in-app purchase fee, just as they won’t pay the Google Play store fee on Android. They claim that with both store’s fees, and the requirement on price parity in-app with their own online store prices makes selling books in-app unprofitable.

I have no doubt that you are correct. I was attempting to avoid the [perhaps] controversial exploration of competing commercial interests of both the Apple and Amazon empires.

Everyone wants a slice of someone else’s pie… 🙂