Earlier quoted context omitted.
From their page: "Patent-pending technology guarantees the integrity of your loyalty program. GPS triangulation, velocity analysis, and statistical variation keep things secure." Velocity analysis. Sounds complicated. Wonder how well it actually works.
Hard to know what to say here, but we (Yell Labs) have built what appears to be the exact same solution to this problem that punchd have. As far as I can tell we started at around the same time but from London, UK. And we have our own patent applications (that I was unhappy about submitting because I don't agree that they were non-obvious, and that punchd did the same thing elsewhere at the same time is evidence of t…
What you need is a device that changes its QR code every few seconds in a cryptographically secure way.