Grocery shopping used to be simple: grab a cart, toss in some produce, swipe a card, and head home. Today, that loyalty card dangling from your keychain—or the app on your phone—does more than just shave a few cents off your total. Supermarkets have transformed loyalty programs into data-collecting machines that know more about your habits than your closest friends.
From tracking what kind of milk you buy to predicting your stress levels, these programs aren’t just rewarding you; they’re studying you. Here’s a closer look at six clever, sometimes creepy, ways your grocery store loyalty program is quietly spying on your life.
