As far as I understand, you offer us to use the services of an intermediary service. As for me, this is not a good idea, and it seems to me to be not a very convenient and safe method of payment. I will wait for the time when it will be possible to make purchases on Amazon directly without intermediaries. I believe that this time will come. Albeit in a few years. In the meantime, I can easily use fiat money. I hope that the year 2019 will be held under the auspices of the introduction of cryptocarrency into the real world economy. This will be a real breakthrough for the crypto-market.