"Below is a list of books you've purchased from Amazon.com that you may upgrade to read online. Select the titles you wish to upgrade, and the total price appears automatically at the bottom."
Of the four books I'd already purchased which were eligible, the prices ranged from $7.99 to $13.99. Amazon is on drugs if they think anyone is going to pay that much on top of what was already paid for the physical book, for the privilege of reading in a web browser while online. At 2/3 that price, and if I could download a regular PDF which I could read offline and with the software of my choice, I'd purchase without a second thought.
Bah. Totally clueless, not unlike selling music online five years ago.