I won't mention the site, but I just saw a blogpost offering tens of thousands of Kindle books for "free". Some of the names of the books are listed and they aren't free books - they are copyrighted books that sell for real money.
So how does he monetise this large volume of pirated material? An affiliate link to a file download site! If you want to download the several GB of ebooks, you really have to sign up for a premium account at the file download site ... and the blogger gets a commission.
Is this where the real money is with ebooks? And is it that easy to get around the Kindle copyright restrictions?