It sounds good, but I don't know if it will last too long. For Amazon and Ebay to become a big thing it took a lot of time and they were the first out there that had international deliveries or from companies that want to sell only there or so. They will probably be the best ones for a long time. But as far as I know you can pay with BTC on Amazon too.
Shopping on Amazon using bitcoins can be done through a third-party site Purse.io, for payment in bitcoins will receive a discount of 5% and more, the site is not entirely correct, not all items are synchronized with Amazon.