Tesco has introduced free Wi-Fi to all of its Tesco Extra stores in the UK. The service is unlimited for anyone with a Tesco Clubcard and limited to 15 minutes’ use every 24 hours for everyone else.

Mike McNamara, Chief Information Officer at Tesco, said: “We’re proud to be the first UK supermarket to offer nationwide access to free Wi-Fi. People are increasingly using a variety of digital services and we’re excited by our customers’ reaction to the new service.”

To use the service, customers simply select “Tesco Wi-Fi” from the list of nearby networks on a wireless smartphone or laptop, then enter their Clubcard details on the web page they’re redirected to.

During a recent survey, 82% of Tesco customers said they would definitely use the service again, while all found it “easy to use.” Other customers said it was “an excellent idea,”, “great service, thank-you”, “great for finding product locations in-store on the Tesco app.”

The survey revealed that 71% of customers access the Wi-Fi via smartphone, 11% via a tablet and 9% on a laptop.

Tesco reckons that the service is useful for reading product reviews and comparing prices while shopping — a comment that has caused raised a few eyebrows.

Last September, Tesco store staff accosted a Guardian journalist making a note of prices using a pen and paper, and claimed the practice was both illegal and against company policy.

Their ridiculous suggestion was that the only legal way to check in-store prices at Tesco was to purchase the items in question and check the receipt…

So, it will be interesting to see if any over-zealous Tesco staff take exception at anyone comparing their prices against Sainsbury’s using a smartphone.