A retail pricing model in which some goods are offered at extremely low prices, while other goods are marked up considerably.
"The advantage of 'high low' is the wow effect," says Ms Bain. "But 'every day low prices' is more of a loyalty-building, 'you can trust us' positioning."
Safeway has demonstrated another problem with "high low". While the number of customers visiting its stores is increasing, it reported sales towards the lower end of analysts' expectations at Christmas.
"At Safeway a lot of shoppers are cherry-picking, so they are only buying when it's 'low' and then buzzing off and buying somewhere else," says Mr Garner at Superpanel.
Heather Tomlinson, "Every little helps Tesco keep its competitors at arm's length," The Independent, April 7, 2002
Traditionally Asda trades well at Christmas and last year was no exception. But the competition got tougher. Asda and Tesco were head to head on pricing across the fixture, while Sainsbury's and Safeway's high low strategies brought them extra benefits.
—Tim Palmer, "Alcoholic drinks: Christmas best sellers," The Grocer, February 24, 2001