Michael,
I buy lots of E-books, from a wide variety of vendors. I have bought two or three from Amazon, but I was very disappointed by the results.

You see, I own my E-books. Yes, I do! That's because I insist on buying only from vendors who offer E-books without DRM, and who sell just the books, not the entire "reading experience."

While it isn't as convenient as being able to open up the "store" on a reader, select a book, and begin reading it immediately, the separation between the mechanics of the sale of the book and the mechanics of the reading of the book is what preserves my privacy.

I'm just not willing to put myself in the position of giving anybody a monopoly on my reading. Because I buy my E-books from many different vendors, no one vendor has that collection of information about what I am reading. Because I read my E-books using software that was developed by, and is distributed by, an organization that doesn't sell E-books, I am reasonably confident that the reader isn't collecting information.

For a while, I was willing to use the Kindle software that Amazon made available to run on general-purpose devices (such as desktop computers and smart phones). However, when Amazon "upgraded" the version of the Kindle Reader for the Android platform so that it would read only books purchased from Amazon (this may have been a bug introduced by the developers, but Amazon made no move to correct the issue), I removed all Kindle software from my devices.

I now use third-party software that enables me to search for E-books on-line, download the purchased (and free) E-books into a library, catalog the library, and maintain the collections of books on my various devices. That's sufficiently convenient for me, and it ensures that I am not the captive customer of any company.