Does not work for non-US versions of amazon
I bought this to try and have a method to pay for a gift for a close friend in Australia as my credit card is not accepted in that country.  To ensure the gift could ship to them, I had to use amazon.com.au and sign in there.  Amazon would not allow me to convert the 50 USD into the corresponding amount of AUD.  Obviously it wasn't a total loss as I could use it toward my next regular purchase on the US site, but it's very inconvenient that amazon does not provide it's customers with a reliable way to pay for and send gifts to friends overseas.
Rating: 3 stars