Over at CNET somebody doesn't like the idea:
Mostly because, since details are limited, he is free to expect the worse.
One thing that came up, though, was Green Stamps. And that got me thinking that Amazon Coins could be another loyalty program in disguise, like Prime.
Amazon said they would be giving lots of Coins away but they haven't said how. So it could be that they could be closer to a Credit Card rewards program than a Second Life styled virtual currency. They might give a fixed amount of free coins with every purchase up to a certain value and above that throw in an added percentage. That way they encourage purchasers of physical goods to try digital goods they otherwise might not consider.
I don't doubt they'll give you the option to buy Coin-age, but it may be that the real goal is to get you to buy DVDs, TVs, clothing, and even groceries--things you're going to buy anyway--and then, since the coins you earn only work for digital...
Might work, no?