SEATTLE – Proving that Amazon Go isn’t just an experiment, Amazon is planning on opening up to six more stores this year in Seattle and Los Angeles, according to multiple sources, Recode reports. In its hometown, Amazon has locked in on at least three other spaces for Go stores, while the online retailer is looking into a location at The Grove in L.A., the outdoor shopping center developed by billionaire Rick Caruso.

The inaugural Amazon Go opened last month after the company spent years refining a system called Just Walk Out Technology, which lets shoppers scan their phones at the entrance, fill a basket and walk out, with the correct amount automatically deducted upon leaving. Some speculate that Amazon will add the system to Whole Foods stores, but that seems unlikely at this time.

The planned expansion of Amazon Go will probably touch off another round of concerns about the fate of cashiers. Currently in the United States, there were more than 3.5 million checkout jobs in 2016, according to the U.S. Labor Department. While Amazon Go has no cashiers, there are workers preparing fresh food, a greeter at the entrance and an employee to check IDs in the wine and beer section.

Amazon also recently introduced free delivery from Whole Foods for Prime members in certain cities as a pilot program. In December, Walmart announced it was also working on technology that would not require checkout.