The Hidden Cost of Loyalty Cards

While these programs are marketed as a way to reward repeat customers with discounts, their primary purpose is to collect "first-party data." This data allows retailers to build deep profiles of your identity, income, and lifestyle. By tracking every transaction, retailers can transform from traditional sellers of goods into high-margin media companies. In fact, profit margins for retail media networks can reach 60% to 80%, which is significantly higher than the razor-thin margins typically found in grocery retail.

Retailers collect more than just your name and address; they use predictive analytics to create a "digital twin" that includes your demographic information, estimated income bracket, and "lifestyle inferences." For example, buying certain vitamins or unscented lotions can flag a pregnancy before you’ve even announced it. These profiles can also include your "dwell time" in specific aisles and your visit frequency. This information is then sold to third parties, including data brokers, insurance companies, and even automotive brands.

Privacy advocates are concerned that retailers use your data to manipulate the discounts you see. Instead of everyone getting the same sale price, algorithms may determine the "minimum" discount needed to get you to buy a product. If a profile suggests you are a "loyal" shopper who will buy a brand regardless of price, you might receive fewer coupons than a "switchable" customer. There is also a risk that "income predictors" could lead to discriminatory pricing, where discounts are withheld based on your perceived financial status.

It is difficult to opt out entirely while still receiving discounts, but you can "limit the harvest." You can use an alias email address for rewards programs, disable "always-on" location tracking in store apps, and turn off Bluetooth features that track your movement through aisles. If you live in a state with privacy laws like California or Oregon, you can legally request to see your data or opt out of the sale of your personal information. For the highest level of privacy, shopping with cash and refusing to scan a loyalty card makes you "invisible" to the network, though you will likely pay the higher "non-member" price.

Any company with a direct financial relationship and a large user base can monetize "commerce media." Banks like Chase and payment platforms like PayPal can see exactly where and when you spend money, allowing them to sell highly accurate "segments" to advertisers. For example, if your bank data shows you bought a plane ticket, they can sell that insight to hotel chains. This "first-party" data has become more valuable as traditional web tracking, like third-party cookies, is phased out.