No, it is trivially easy to put non-DRMed books onto a kindle. One publisher who I find particularly reader-friendly is Baen. If I buy a book from them, it go

No, it is trivially easy to put non-DRMed books onto a kindle. One publisher who I find particularly reader-friendly is Baen. If I buy a book from them, it goes into my account there so I can download it at any time (and any number of times) in the future, in a wide variety of formats. Since I do my reading on a kindle, I click the send to kindle link and it pops up next time I turn on my kindle's wireless.