Aldi is taking advantage of the credit crunch to emphasis how cheap it is compared with the big four.
The discounter is running national newspaper ads comparing its prices for 22 common products against each of the multiples using the slogan 'Don't change your lifestyle, change your supermarket'.
"We wanted to be explicit about the saving we offer customers and how we compare favourably to our competitors," said Paul Foley, Aldi UK MD.
"An independent journalist researched the prices, so what better way to communicate the saving by repeating the core findings in a print advert?"
The advertisement would emphasise the retailer's low prices, said Foley. "Over the past few years, we have focused our communications on quality," he said. "This current approach reminds customers of our core offer, fantastic prices and value for money."
Aldi's total shopping bill came to £37.45 in the research compared with the next cheapest retailer, Tesco, at £44.57. Morrisons was the most expensive at £50.02.
TNS for the 12 weeks to 20 April 2008 shows Aldi performed particularly well, with sales up 17.4%. Its market share has increased from 2.5% to 2.7% compared with a year ago. "Current conditions have seen accelerated footfall and sales figures but our offer will continue to resonate regardless of the economic climate," said Foley. "There are some monthly expenditures that are beyond the control of the customer. However with groceries, customers can make the switch to Aldi."
Aldi plans to open stores at a rate of 40-50 a year, and is investing £20m to expand in north Wales over the next 12 months. Four new stores will open this year, the first of which, at Porthmadog, opens on 5 June.
Planning permission has been gained for a store at Old Colwyn and applications are being considered for Llangefni and Flint.
Aldi currently operates seven stores in north Wales.