Amazon does not sell ePub books

Nor does Barnes and Noble. I already know this. They want to keep you in their ecosystems to maximize profit and make sure you always buy another of their devices. And that is precisely the problem.

I went through this before during the first 5 years of iTunes store and I don;t really want to go through it again with books. I don't mind a reader being tied to a particular store for convenience but I would at least like the option to buy elsewhere.

So are there any stores selling books in ePub format who have any real selection?