This is really cool. However adoption will be a really challenging issue. When you end up having to upgrade your pos to print these qr codes (with little incent

This is really cool. However adoption will be a really challenging issue. When you end up having to upgrade your pos to print these qr codes (with little incentive) you could just end up switching to a square-esque system instead. I think the Json format is cool. Qr codes as a representation should be one way of sharing it.