In brief: Computer vision isn’t only good at tracking faces. Walmart has revealed that it is using tracking systems in order to reduce “shrinkage” – lost revenues due to theft or items going unscanned.

There have been plenty of big stories in recent months about computer vision being used to track people in stores or going about their daily lives, but Walmart has revealed to Business Insider that it has invested half a billion dollars equipping 1,000 stores with technology to track items instead.

The computer vision solution tracks products at self-checkouts and regular manned stations, and alerts staff if it sees an item leaving the store that hasn’t been paid for.

The company said that this is an effort to reduce “shrinkage,” a retail industry term for lost revenues through theft or human error. While you may think theft to be the bigger problem of the two, it’s purportedly accidents that end up hurting the bottom line more.

According to Alan O’Herlihy, CEO of Evergreen, the company that makes the computer vision technology, customers may leave items in the bottom of their cart by accident, or cashiers may not properly scan items if they’re not paying attention. He said, “people make mistakes – in terms of ‘shrinkage’, or loss, that’s the main source.”

Walmart itself has also billed this as a move to protect itself from theft. LeMia Jenkins, a spokesperson for the chain, said, “over the last three years the company has invested over half a billion dollars in an effort to prevent, reduce and deter crime in our stores and parking lots.”

It’s an interesting move, and is certainly a safer bet for the company from a reputation standpoint. There are no privacy concerns to grapple with, so the policy and associated technology is unlikely to cause much consternation among customers. According to Business Insider, shrinkage cost US retailers an estimated 1.33% of their bottom lines in 2017 – which equates to roughly $47 billion.