You are correct.
It's no more than it claims to be: a comparison of those three stores, which are the ones I looked at. I was addressing your statement that there were only a few pennies difference between Sony and Amazon prices for the same items. That list was not one I created for this thread (which I should have made clear), I did it a few weeks ago for my own amusement before I visited any of the other MOBI stores you mention. It's not up-to-date, merely illustrative at that point in time for those stores. The purpose was to see if I would have been better off with a Sony reader. I didn't investigate the MOBI format further, as I determined that the Kindle was the more attractive choice for me at this time for newly published books.
I was just too lazy to delete the MOBI figures.
