LONDON: Tesco, the UK supermarket chain, is installing face-scanning technology at its petrol stations in order to tailor advertisements shown to individual customers waiting at the till.

A camera and software is used to identify a customer's gender and approximate age before showing an advertisement tailored to that demographic.

Tesco plans to roll out the technology across all its 450 forecourts in the UK and expects to reach 5m people. "The ability to tailor content based on time and location means it can be extremely useful and timely for our customers," said Peter Cattell, category director for Tesco petrol stations.

The supplier, Amscreen, meanwhile, is hoping this is just the beginning. "This could change the face of British retail," chief executive Simon Sugar told the BBC, "and our plans are to expand the screens into as many supermarkets as possible."

A Tesco spokeswoman sought to reassure consumers worried about privacy. "No data or images are collected or stored and the system does not use eyeball scanners or facial-recognition technology," she said.

And Ke Quang, chief operating officer at Quividi, the company that developed the software, echoed her remarks in an interview with the Guardian. "We don't do facial recognition, we do face detection," he stated.

Inevitably, not everyone was convinced. Nick Pickles, of the pressure group Big Brother Watch, said there was "a huge consent issue".

And Philip James, joint head of technology at Pitmans law firm, said that while the technology operated in a similar way to social media sites tailoring adverts to users based on the content of their profiles, "the capture of facial signatures represents a potentially much greater infringement of customers' privacy in the absence of prior consent".

But others were more sanguine. "People will accept it as long as they get rewarded by it," said marketing and technology consultant Tom Cheesewright, "if you see an interesting advert rather than one that bores you".

Data sourced from BBC, Guardian, Reuters; additional content by Warc staff