You have a good point. I just got the costco citi credit card, and there was a small pamphlet included with the privacy information and what data is shared. Basically something like 8 line items for different kinds of data, 5/8 were required, the other 3 I had the option to opt-out, but they were automatically opt-in.

At the end of the day, the benefits far outweigh the meta-data that is shared. Ok, sure you can see what I ordered at costco and how much I spend on gas.

Yes, it's a data grab by companies, but what are you gonna do... not take 4% back on gas and 3% on restaurants?