Kroger knows every purchase you've ever made – and says it could make millions of dollars selling your data

• Grocers like Kroger are gathering consumer data and selling it, The Markup reported.
• Kroger says that selling the data to advertisers could help it realize $1 billion in new profit.
• But the information, even without names attached, could violate customers' privacy.

Major grocers aren't just moving produce or TV dinners anymore: Many are also selling detailed information about customers' purchasing habits.

The data is valuable to big food brands, which advertise to consumers and don't have detailed information about who is buying their products once they make it to supermarkets, according to a story that nonprofit technology newsroom The Markup published on Thursday. Supermarket chains are filling that void by selling those brands the information that they collect from customers, including when shoppers place a delivery order online or use a loyalty card at a checkout in-store, The Markup reported.

For the grocers, the rewards are potentially significant: Kroger, one of the US's largest grocery chains, has said that data is one of a few "alternative profit" businesses that could add $1 billion in profit to the company. Right now, those businesses generate about $150 million in profit, The Markup reported. Kroger operates grocery stores under several names, including Mariano's and Ralph's.

Kroger did not immediately respond to Insider's request for comment. Albertsons, which owns chains including Safeway and Vons, told The Markup that it takes privacy seriously and updated its privacy policy "so customers can clearly understand our approach to privacy and the policies that we have put in place to protect their information."

Both Kroger and Albertsons say that they give aggregate "de-identified" shopper data to their clients. But even without someone's name attached to it, a shopper's data can be identifiable, according to The Markup. One study found that just a few purchases with details like total spent, purchase date, and which store the purchase was made at was enough to identify specific shoppers.

The grocers also package the data to help advertisers target specific groups. Kroger, for instance, touts its data set on Hispanic consumers, among other "ethnic panels," on the website for its marketing arm.

About 60 million US households shop at a Kroger store, according to the company. That number, and the company's data pool, could grow to 85 million if Kroger's proposed $24.6 billion merger with Albertsons wins federal approval.