Amazon Expands Cashierless Technology Testing Inc. (NASDAQ: AMZN) has expanded the testing of its cashierless checkout technology. The online retail giant is reportedly experimenting with the technology in Seattle, Washington in a large space formatted like a big store. According to a source with knowledge of the matter, the technology works well in a small store format but is harder to use in bigger spaces with higher ceilings.

The company first started using the technology at its Amazon Go brick-and-mortar grocery store in Seattle. The store, built without lines or checkout counters, allows customers to buy things with the help of a smartphone app that tracks what they pick up and put back. The store bills their credit cards for the items after they leave the store.

There are reportedly plans to open as many as 3,000 Amazon Go locations across the nation. However, Amazon seems to still have some glitches to work out with the technology. According to reports, the technology has issues with differentiating individual shoppers who looked vaguely similar. It also reportedly has problems with people who moved too fast and merchandise being moved.

It is clear why Amazon would want to adapt the technology for use in bigger stores with larger spaces. A likely use would be to use the technology at its Whole Foods stores, acquired in 2017. It is unclear whether Amazon intends to use the technology for Whole Foods, as the company previously said it has no plans to add the technology to Whole Foods.