> your CC payments help track

Not only that. Them and the point-of-sale vendors (aptly shortened PoS), sell that data. They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.

The websites (and even their retail locations) you buy from send your purchase data to meta and other advertisers directly via APIs so they can better track their marketing conversion rates. You can browse their APIs [1][2] to see what kind of data they like to get, but it tends to be every piece of identification they have on you. Rewards programs make this a much richer data set. You don't need to be a user of Google/Meta for them to build a marketing profile based on this. Google links your physical conversion from ads based on your maps data. Facebook does the same if you give them your location data. Many retailers attempt to use the bluetooth/wifi signals from your phone to track the same data even if you pay in cash [3].

There's no legal framework preventing this outside of the EU and California.

1: https://developers.facebook.com/documentation/ads-commerce/c... 2: https://developers.google.com/google-ads/api/docs/conversion... 3: https://www.nytimes.com/interactive/2019/06/14/opinion/bluet...