Dozens more Amazon Fresh stores are set to open in the UK, the Times reports.
The online giant has just opened its first such store in Ealing in west London - but is already understood to have plans to expand far beyond that.
The shops operate using technology that allows shoppers to shop and pay later.
Rather than paying at the till, an app tots up the items picked up in store and charges them directly to the bank card attached to their Amazon Shopping app account.
The Times says Amazon is believed to be planning 20 more store openings a year from next year - and says deals are already in place for around 25 sites.
Those sites are reportedly mostly in the capital and its suburbs, but the Times says that Amazon will also be expanding to other cities.
The news comes after Mirror Online reporter Talia Shadwell visited the new store in Ealing to see what it was like.
She said: "The fare is of similar pitch and quality appearance to Waitrose - think fancy ready-meals, a large ravioli range, hoisin duck wraps, on-trend chocolate-orange desserts."
A coffee machine in operation at the store was not working, she said - prompting worries that people would be charged for something they did not get. However, a member of staff quickly came out to fill it up.
Buying alcohol was done in a different way, she found, as there was a locked gate that a worker opened to grant Talia access to a sealed-off section.
Elsewhere, there were meal deals, sandwiches and other standard supermarket fare.
Talia said after her visit that she had not been aware that her purchases would not be added up as she was in the shop, and when she left she had no idea how much she had spent.
"I polled four shoppers outside the shop, and not a single one could tell me how much they had just spent," she said.
"We were all so charmed - or perhaps fooled - by the novel experience of wandering around the store popping items in our bags: we had forgotten to do our mental maths."
