The idea of facial recognition as a form of security has been around significantly longer than the technology itself. It's in sci-fi and spy movies dating back to the 80s. The idea to use it as a means of authorizing payment should have been considered obvious by the clerk that granted your patent, but it wasn't, and that's where software patents are failing hardest today.

I think a lot of folks would agree that face-based payment authorization as an option would have come along eventually, just as every other biometric and security device will eventually get applied to everything anyone might want to secure.