Amazon has just hammered another nail in the coffin of brick-and-mortar retail by opening its first checkout-free grocery store, Amazon Go.

How does it work?

The 167-square-meter store has been set up in an Amazon office building in Seattle. It’s fitted with a system that automatically detects when products are taken from or returned to the shelves and keeps track of them in a virtual cart. When a customer using an Amazon Go app is done shopping, they can just leave the store. Shortly after, Amazon will send them a receipt and charge their Amazon account.

What does it sell?

Ready-to-eat meals for breakfast, lunch, and dinner. There’s also a big selection of grocery essentials like bread, milk, and chocolate.

Has it worked the way it should?

Reuters reported there had been a few teething problems. These included difficulty in correctly identifying shoppers with similar body types, and when children were brought into the store during the trial, they caused problems by moving items to incorrect places.

When will we see this technology elsewhere?

Amazon is remaining tight-lipped about whether it will add more locations, and it stresses it has no plans to transfer the technology to Whole Foods, the high-end supermarket chain it bought last for $13.7 billion.