I agree that it was obnoxious for Amazon to choose the mobi format instead of epub, but in practice it's not a big deal. I use the open source Calibre program.

I agree that it was obnoxious for Amazon to choose the mobi format instead of epub, but in practice it's not a big deal. I use the open source Calibre program. Among other things it will translate among mobi, epub, pdf and a bunch of other formats. There is really no effort involved. You just hit OK when it asks whether to convert the book before transferring it. You can also email an epub to Amazon and it will come back immediately in Kindle format and this method also works well. There is no charge for wifi but there is a charge for cellular delivery. I think the Kindle is admirably compatible with third party publishers or self published material, much more than Apple's locked down and toll collected ecosystem.