People get the choice all the time with loyalty and reward points cards. It's pretty much a unique identifier that people carry in their pockets and handover willingly every time they make a purchase. It's more obvious and in-your-face sure, but the principle is the same and they have the choice.

Personally, I handover all my fitness information, driving habit information, spending and banking and investing information, my health information, even my location data, my STD statuses, etc to a company so I can get massive discounts on a bunch of stuff in various ways. It alters my behavior in a good way, it alters other peoples' behavior too, and I'm all the more happier about it. I much prefer this over stupid things like sin taxes, consumption taxes and laws that most people don't stick to or agree with (talk about choice and consent, huh).