I try to support publishers that give you the full ebooks like baen library.

Calibre helped me back up my entire amazon library in a way my kobo can now read instead of just kindle. Both are excellent devices, but I wanted a backlight after 7+ years with the same ebook reader. And I’m not about to purchase all those books aain for the privilege of using the kobo bookstore. Plus Calibre makes it so no matter what you get (pdf/ebook/proprietary format) you can get a good old fashion ebook format for future preservation.