That would be way too easy to game. I.e. set up an Amazon Marketplace account, "sell" yourself and/or accomplices lots of books for "reasonable" prices, with the money minus some vig including Amazon's charges going back to the "buyers", then they buy el-cheapo Kindle copies for real.
A hint as thinking doesn't appear to be your strong point. If something seems to be "way too easy", even to you, perhaps they thought of it first. That might explain why this applies to purchases from Amazon only.
That would be way too easy to game. I.e. set up an Amazon Marketplace account, "sell" yourself and/or accomplices lots of books for "reasonable" prices, with the money minus some vig including Amazon's charges going back to the "buyers", then they buy el-cheapo Kindle copies for real.