I came to the conclusion a while ago that you don’t buy ebooks from Amazon, you are only leasing them.
First off, the highly restrictive Amazon DRM not only limits access to the ebook to their proprietary Kindle device, it restricts it to your specific device. Once you are done with the ebook, you can loan it to friend or sell it at used book store. If you want your friend to read the book, you have to give them your Kindle, because that is the only place that ebook will be displayed.
Second, Amazon doesn’t pay it’s associates a fee for any Kindle books “sold” through them. Why not? They pay the associates for just about everything else sold through their sites. Could it be that Kindle owners really are not “buying” the ebooks, but are just paying for a very restrictive lease in order to access the ebook?
…there is always a limit to the number of times you can download a given book. Sometimes, he said, it’s five or six times but at other times it may only be once or twice. And, here’s the kicker folks, once you reach the cap you need to repurchase the book if you want to download it again.
I know people who buy paper books in both hardcover and paperback, but that is a different scenario. You have two separate versions of the book in different formats. One for the shelf and one to carry around and loan to friends. Amazon wants its customers to buy the exact same content, in the exact same format, multiple times, because their business model assumes that their paying customer are thieves.
That is not a consumer friendly business model.