That is really what supermarketloyalty cards provide—shoppers are supposed to think that the store is grant-ing them a discount in appreciation for their steady business, but actually thestore is paying them for information about their buying patterns.
I find this a bit shocking as I never thought about this but I'm not surprised as the corporation gets the true financial benefit by collecting the consumers data. This is also an example that reiterates what I mentioned earlier about 'there is no such thing as a free lunch. In this case, it's the discounts that would cost the consumers their data.