My regular supermarket is Safeway, and I use the frequent shopper card. So every Wednesday I get an email listing weekly specials, including specifically stuff I’ve bought before. Sometimes it’s stuff I regularly buy but other times, it’s something I bought once but don’t normally get.
Yes, that certainly happens a lot. At the store itself (and probably at corporate HQ for big chains) they certainly do track what you buy for their in-house advertising. Who knows whether they may, furthermore, be selling that kind of data to outsiders like the big Internet companies, Google Advertising, or whoever.
But my point was, contrary to apparently common belief, it’s not your credit or debit cards that are tracking all that.
ETA: That’s also the whole point of those “Club Cards” that stores push, by whatever name they call them. Otherwise, they have no idea who their shoppers are (they don’t collect that from your credit or debit cards), but when you swipe your club card, of course they get your name and in-house account numbers, and they’ll have your mailing address, account information, and all that. Same thing when you sign up for house charge accounts at department stores.
[quote=“Senegoid, post:20, topic:920810, full:true”]
Let’s clarify one thing: It’s a paranoid and incorrect notion that your purchases by bank card are being tracked item-by-item. When you present your bank card as payment, the only information transmitted is your identification information (name, account number, address), the merchant’s identification information, and the amount of the sale. The only information received in return is accepted or declined.
The detailed list of items you buy may well be collected via channels. For example, consider those Catalina printers at many supermarkets – they look just like receipt printers, but they print out customized coupons good for the future purchase of items similar to things you just bought. That whole process is handled by an outside third party. The cash register transmits your entire purchase detail to Catalina, which then prints out those coupons. I have no idea what more Catalina does with that information, but it is being sent.
(My cite: I worked for a cash register company, where I did the detailed programming to interface our registers to Catalina for those coupon printers. ETA: And I was also involved in the detailed programming for doing the credit/debit card interfaces.)
Modern cash registers, of course, are all computer-based database machines, and they record the full detail of every purchase, which may be stored for days or weeks or however long the store wants. In the case of big chain stores, the full detail of each day’s purchases may be transmitted to corporate headquarters, and there’s no telling what they may do with the data. (The primary use, of course, is for inventory management.)[/quote]
I’m sure the data is mostly anonymized, but big store chains are certainly spending fortunes to have data scientists develop all sorts of machine learning algorithms to figure out people’s purchasing patterns.
I believe such places usually use a more discrete name on your credit card…or so I’m told. 
Right, and the card brands, who have no real skin in the game other than the transaction fees–plus what they can get selling the data.
In theory, they’re just networks connecting processors to issuers. In reality, they’re also data brokers.
AX is of course the quasi-exception, being both a brand and an issuer.
Yeah, yeah, they might tell you that. Maybe some do and maybe some don’t. My cite: You needn’t ask.
As for your above remark about data being anonymized: Not necessarily. If you’re using a “club card” or “frequent shopper” thingy or similar or if you otherwise tell them who you are, they can certainly (and some do) keep detailed logs of your purchases, and may use them for future advertising, and maybe even sell you data.
My point was simply: They aren’t doing this via your debit or credit cards.
Yep, this is it.
Actually, cash is principally a boon to criminal activity.
It wouldn’t surprise me if the person is also very much scared of the Mark of the Beast, and the idea that you can’t buy or sell anything without a mark on your hand or forehead. I’ve seen some interpret this as some sort of subdermal microchip that they say will eventually replace credit cards, to prevent fraud.
I’ve heard less of this in the Internet age, though, since online purchases make that whole idea less tenable. But those are also cashless interactions, so OP’s guy probably hates them, too.