The reaction from rivals to Asda's new and improved Price Guarantee scheme this week has been one of contempt.

It was a gimmick when it launched eight months ago, they say, and it's still a gimmick.

As I recall, Sainsbury's said as much when Tesco introduced its Clubcard in 1994. And while I'm not suggesting APG will be as successful as the Clubcard, the changes introduced to the scheme by Asda this week guaranteeing to be at least 10% cheaper or your money back make me loath to dismiss it as just a tweak, especially when it comes, we are told, with "Walmart's backing". This would appear to be code for "parking one's tanks on Tesco's most profitable lawns".

The Price Guarantee scheme got off to a very slow start and even with improved marketing, the total number of redemptions is a drop in the ocean versus Clubcard. As well as the audacious 10% promise, it needs to make the scheme easier to understand, and to use.

In particular, the reliance on the user to return home to check the price is a major obstacle. But the advance of technology suggests it may not be so for long.