We can already fingerprint digital devices and make pretty good guesses based on purchases and geofencing (leaving the area) whose fingerprint goes to which dig

We can already fingerprint digital devices and make pretty good guesses based on purchases and geofencing (leaving the area) whose fingerprint goes to which digital device (especially over repeated visits). I haven't heard of a company that offers this at scale or to cross-reference the information, but I can't imagine it'll take long. It's just a matter of some elbow grease for engineering and the right sales team.