The computer whizz who played a key role in Tesco's decision to abandon its Double the Difference deal has been unmasked by The Grocer - and revealed he now has Asda in his sights.

David Whitehouse, 32, a Middlesborough-based web developer who works for a leading non-food retailer, created in his spare time.

The website, now rebranded as, hit the headlines after highlighting significant price differences between Tesco and Asda, guiding shoppers to refunds in excess of £100.

"I started the website when I discovered that people wanted to identify products that Asda sold cheaper than Tesco," said Whitehouse.

"Tesco showed the 10,000 items it compared on its Pricecheck website, but there was no easy way to just see the items that were cheaper at Asda. So I created a website that extracted that information and organised it into one list. It only took a few hours."

Whitehouse then posted the link on Forum members who were already lapping up Tesco's offer raved about the site, calling it "fantastic" and "amazing" after it saved them trawling through hundreds of posts to spot a great deal. "I was surprised at the interest," he admitted.

Tesco responded to the surge in refunds by capping vouchers at £20. But then the site hit difficulties.

"When Tesco introduced the cap, it also claimed there was a technical hitch with the Pricecheck website, which was then removed and has never returned," said Whitehouse.

"That hampered my progress for a short time. But now I use price information from the Tesco and Asda websites. Plus it updates itself every 24 hours."

Last week Tesco was forced to ditch Double the Difference, instead offering to refund just the difference. It pinned the blame for its backtrack on "savvy and determined people" who exploited the promotion "just to make money".

"If I had been in Tesco's position I wouldn't have offered the Pricecheck feature in the first place," said Whitehouse. "It invited people to take advantage. Tesco is portraying itself as a victim when by and large the people taking advantage followed the terms and conditions set out by Tesco. I hoped Tesco would solve its problem by lowering its prices in line with Asda, instead of what seems like admitting defeat in the price war."

Whitehouse added that he has no problem with Tesco, just "questionable" supermarket promotions, and vowed to expand his website soon.

"I am also going to take advantage of the Asda Price Guarantee and show Asda shoppers the items available cheaper in Tesco," he claimed.

No, he isn’t working for a rival retailer...

When Whitehouse's website launched, its lack of any branding led to speculation that it had been created by one of Tesco's rivals in order to scupper the retailer's offer.

However, he denies that he is working for anyone else, and insists that he has no axe to grind with Tesco or with any other supermarket. He simply built the site "so people can get the most value from their shopping."

Read more
Tesco’s Price Check becomes ‘just the difference’ (28 April 2011)
Party is over, but what’s the damage to Tesco from Double the Difference? (2 April 2011)
Tesco closes pricing loophole exposed by mystery website (25 March 2011)