They didn't go for it :-)

Back when my kids were young and we had a neighborhood baby sitting co-op, all the Mom's met once a week. We set up a program where we got 15 different cards, every week we put all the cards in a basket at the beginning of the get together, then everyone took a card when they left (the basket was shaken up to randomize cards). That gave everyone a card to use but only aggregate statistics on the whole group rather than individual statistics.

The name was always Jane Smith.

These days Safeway has "fixed" that practice by tying gas rewards to a particular card number. That forces people to use the same card if they want to get gas rewards. I don't know but I suspect it was in response to activities like ours which mitigated their efforts to collect data.

In fact, you can often keep the activated card (at all kinds of stores) even if they do ask you to fill in some papers. Just ask to take the forms home to fill them in and return later and take the card, too.

Now without the baby sitting co-op to randomize data I've offered my card to people ahead of me in line who don't have one, but again the gas rewards are changing that equation as well.

I've long since avoided Safeway (going on two decades), but back when I both visited the store and had a card, but under a different name (usually some variant of "Fred Flintstone" or "Mickey Mouse"), I found that my actual name eventually ended up on the receipt if I every paid by check.

Lesson: don't pay by check.

Lesson: don't patronize stores with shopper surveillance cards.

Most recent notable experience: a few visits to Border's Books, in which the store's "loyalty card" was pushed ever more vigorously. I responded "no, the NSA's already listening to my phone calls and reading my emails, no need for them to get my reading list as well" (this was years before Snowden, though after the AT&T listening room was revealed). The cashier was impressed by my integrity, and commented as much, as I paid cash for my purchase.

The last time I was asked if I had their card was during the final week of the store's liquidation sale. And I was thinking 1) why even bother and 2) where will that data go after the company shuts down (it turns out it was bought by Barnes & Nobel, which may itself go the way of Borders before too long).

So. Yeah. I'll pass.

As a non-USian who does not know this system, can somebody please explain what "gas rewards" are and why they would prevent the kind of card shuffling explained by ChuckMcM?

The size of the discount is tied to the amount of purchases made with that card present. So if you make a lot of purchases you get a bigger discount per gallon at the gas station.

If you share the card or exchange it with others, the first one to use the discount gets that savings, the next person does not. The discount resets on use, and it can be re-established by the next set of purchases on the card.

What that does is creates an economic incentive for someone to use the same card (maximize purchases to maximize discount) and not share it (discount is one time only, and to the current holder of the card.)

you could still pool all the cards and split the reward between you, couldn't you?

In the US, most large grocery store offer a card that you can use which gives you various rewards, and in turn allows them to perform analytics on their customer base.

Historically, these rewards were related to coupons for products in the store. However, this means that there is no benefit to using your particular card instead of someone else's.

More recently, the grocery stores have added other bonuses. The one that I'm most familiar with is for fuel / petrol. They team up with some fuel brand, say exxon, and when you've purchased enough on your loyalty card, you get something like $0.05 of your per gallon fuel costs.

The scheme with the poster above breaks down, because you need the physical loyalty card to use the fuel discount, and it's unlikely that everyone is refueling their car an equal amount each week, and that everyone is purchasing an equivalent amount of product at the store each week.

Same goes for every one of the thousands of products we purchase, isn't it a waste of time, money, and national health to put the responsibility of researching products and services in the hands of individuals? Why are companies allowed to sell me snake-oil, cigarettes, and other harmful products?

Why isn't there a law that prevents marketing data from being tied to personal identifiable information?

and

http://www.forbes.com/sites/kashmirhill/2012/02/16/how-targe...

Show that individual data can be and is accessed.