Exactly. Being concerned about privacy doesn't mean that you don't have a price at which you'll sell specific data of yours.

We need these "personal data for discount" transactions to become more explicitly consensual. Despite the well-tuned sensitivities of those in this community, we have a long way to go before most consumers are informed about this unwitting marketplace.

The trouble I see coming is, right now it's "a discount" for sharing the data. Once these sorts of services become ubiquitous and well tested, it'll be "a surcharge" for not sharing the data. Explicit opt out, versus explicit opt in. Right now, it feels like you're getting value out of sharing your data, but in the future, you may have to pay more (relative to others) to keep your data private.

They're two sides of the same coin. Your situation is already the reality. A 40% discount for selling your information is a 67% surcharge for your privacy.

That's a matter of perspective, and I agree that that's what it will very rapidly become. However, right now, I would say it really is a discount - you get a rate that is lower than what you would otherwise have gotten before the technology was introduced. That's partially a reward for you being part of the early adopter group that will make it ubiquitous enough that they can justify raising the prices back up to the level the market can bear.