1 AMZ is equivalent to 1 $10 Amazon gift card.
I see why you're doing it that way, setting the divisibility to 1, and I'm not recommending you change it at this point. But, for anyone else considering doing something like this I'd recommend having a "1 XYZ = 1USD of xyz" exchange (or CAD or EUR or whatever) for items that have a face value on them. In otherwords I'd have recommened using 10 AMZ = 1* $10 gift card. So that x*AMZ ~= x*USD and you'd have a redeemption divisibility of 10 for now. That way if in the future if you were to support $5, $10, $25, and $50 gift cards it would be straight forward how to interchange them and the only thing that would have to change is your divisibility on redeemption. All just my opinion of course, maybe others find the 1 => $10 thing easier.
1) I will send 1 $10 Amazon gift card for every 1 AMZ sent to me (free US Shipping)
Excuse my ignorance, but do Amazon gift cards have a code or something on them that can be used for online purchases? If so is it possible for someone to just ask for you to PM/e-mail them the code and save you the cost/effort of shipping? And also being able to use the code right away without waiting for snail mail.
A market currently exists in the AMZ (bitaccumulation) / XRP in ripple.
To those interested, there is also (as I write this) an offer SELLing AMZ-bitaccumulation for USD-Bitstamp (as one might have expected). Type AMZ/USD into Ripple's trading interface and enter the appropriate issuers to see the order book and add offers.
Finally, not to steal your thunder, but for non-US people, I'd like to point out
Ripple Union's Amazon.ca
giftcard exchange and
proxy buying services for those that can't make use of US Amazon cards. It apears the limits/fees they charge have changed since I last looked however so for US people bitaccumulation's offer looks to be a better deal. (You can purchase Amazon.ca codes internationally and use them to fund your Ripple account in CAD-RippleUnion and then trade for USD-Bitstamp if you so desired.) Disclaimer: although I'm not affiliated with RippleUnion, I know the operator(s) and have held/traded CAD-RippleUnion in the past. (And again, I don't mean to derail this topic, if anyone has comments/questions about RippleUnion the operator(s) read and post on the Ripple.com forums so I'd point people there instead of derailing bitaccumulation's topic).