In the good days I'd go to books and I had a default set of where to deliver. Usually my Kindle library. But I could set it to send everything to my Kindle if I wanted. Or for one book I could choose to send it to my backup rather than my default. Now every purchase has nothing except "Deliver to your Kindle library". If you hover over that it says you can send it anywhere using manage content and devices. Ok, fine. Put it all in the library and when I want it I'll send it to my Kindle. But STUPID Amazon doesn't do that. It sends it ALL to my Kindle which fills it up when I don't want that. How do you make it do what it says it will do?