If you're using Samsung Pay, here's an easy way to get a $10 Amazon gift card. Just use Samsung's contactless payments service three times from now until the end of the month, and a $10 Amazon gift card will be added to your Samsung Pay wallet.
As is the case with such promotions, there are caveats. Bank of America Visa debit cards private label (PLCC) cards added to Samsung Pay before March 31, 2016 are not eligible. The promotion is limited to those on the Galaxy S6, S6 edge, S6 edge+, S6 active, Galaxy S7, Galaxy S7 edge, Galaxy S7 active or the Galaxy Note 5.
There's no set minimum for a purchase to be counted as a "qualified purchase," which means that you can technically get the gift card by using the payment service at a vending machine. Just make sure you make three purchases before August 1. Samsung Pay works with NFC as well as MST (Magnetic Secure Transmission), making it compatible with older machines with traditional card readers.