I would under no circumstances use the coins as a normal cash / change.
In order to keep track what you od for his Kindle HDX. FTV to Apps month buys but it is a good thing.
Return problems to stand at 0 unnecessary - with the constant offers you can do that for sure with time. More than 9 in Coins (equal to 1000 coins) you need eh never the same - can not understand the criticism in the direction.
Who already exchanged more than that in "play money" to? Otherwise the coins actually, and that should one at any time be aware at all of the convenience!