Square as a company isn't tied to credit card processing. Credit cards just happens to what's popular now. If NFC takes off, the company will run with it. When

Square as a company isn't tied to credit card processing. Credit cards just happens to what's popular now. If NFC takes off, the company will run with it. When that happens, the shops just need a new attachment or a device upgrade, the software just works. i.e. this would be how I would have done it.