I think the redemption cost for AA miles is way too high.
A $10 Amazon card is 1081 points. That works out to about .93 cents per point.
100 AA miles is 413 points. That works out to around .35 to .60 cents per point (depending on how much you value miles). It just doesn't make sense to redeem miles for such a bad exchange rate when much better rates are available. Also, the gift cards are much more easily liquidized that miles.