If you dare give your app away for a day or allow another marketplace to do so, and sell your app via Amazon now or at any time in the future, you must permanently reduce your minimum list price at Amazon to $0.00 meaning that from this point they could give your app away for free as often as they like and give you nothing (0.2x0.00 == 0.7x0.00 == 0.00).

Essentially this means you can't give an exclusive offer to anyone other than Amazon, including via your own site if I'm understanding correctly, without also giving Amazon the option of the same offer (meaning is isn't much of an exclusive) and not just now: they have the option of running the offer when-ever and how often they like now and at any time in the future.

"Furthermore, Amazon dictates that developers cannot set their list price above the lowest list price "available or previously available on any Similar Service." In other words, if you want to sell your content anywhere else, you cannot prevent Amazon from slashing the price of your game by setting a high list price. And if you ever conduct even a temporary price promotion in another market, you must permanently lower your list price in Amazon's market."

This seems to imply that if you offer your app in a free-app-a-day promotion, you're required to offer it for free permanently to Amazon, although there's no way that can be correct

[Edit: it seems I misunderstood the parent comment. I'm referring here to free-app-a-day promotions like this http://www.freeappaday.com/. I wan't aware Amazon offered something similar

I was saying it looked like if a developer promoted their app on a site like this, point 9 make it look like they'd be forced to offer it for free, forever, on the Amazon store]