Amazon said on Tuesday that it is closing its Fresh grocery and cashierless Go convenience stores as the online retailer backtracks on its foray into brick-and-mortar retail. 

Amazon said some physical store locations will be converted into Whole Foods Market stores. Amazon Fresh will continue to exist as an online brand, the company said. 

“While we’ve seen encouraging signals in our Amazon-branded physical grocery stores, we haven’t yet created a truly distinctive customer experience with the right economic model needed for large-scale expansion,” the company said.

Amazon said its grocery business, which it launched more than two decades ago, accounts for more than $150 billion in gross sales annually. The company bought Whole Foods in 2017 for $13.7 billion.

Amazon Go stores’ technology allows registered customers to take what they want from store shelves and walk out of stores, without needing to check out.

The company also said Monday that the technology has been deployed at hundreds of third-party locations across five countries, allowing shoppers to “simply take what they need and go.”