Retail sales rose in November, which surprised many people, including retailers. Perhaps they should not be shocked; after all, they have been ruthlessly focused on their customers for months.

The high street has become a blur of red “sale” signs. Although some have gone up in the past few days, many retailers have been quietly - and not so quietly - discounting for weeks. Consumers, always eager for a bargain, have been shopping around. For the newly hard-pressed middle classes, it is OK to shop, as long as you don't pay the price stated on the label.

There is a long-term and important lesson in this. Customers are still out there. During the downturn, the top priority has to be to keep them. This is not simply a tale of pricing. Consumer attitudes are shifting more widely. Research this month by GfK NOP, a market research agency, found that discretionary spending had fallen sharply. In particular, consumers are wary of committing to substantial expenditure on items such as cars, furniture and electronics.

However, consumers' increased price sensitivity and their unwillingness to take on more debt do not mean that expectations about quality and service have dipped. Consumers are comfortable with the idea of their bank - or any other provider - cutting costs, so long as that does not involve spending more time queueing in a branch or on hold in a call centre.

Compromising the quality of products and services will only cause retailers to lose customers. Some shoppers will turn elsewhere because there normally will be a competitor who can undercut on price. Many more will leave in the future when, as the recovery comes, they migrate to companies that have continued to offer high-quality products and exceptional service through the downturn.

Just because customers want discounts at the moment does not mean that that is all a company need provide. Sometimes it is better to increase value than to compromise on price. A recent Management Consultancies Association survey of senior consultants who work with 90 companies in the FTSE 100 found that businesses in general have not invested anything like enough time or money in planning or in improving their products and services so they keep customers during the bad times. Too many companies did not anticipate the downturn and were not ready when it came.

Two things are making the situation more difficult than it might otherwise be. First, marketing has always been the first casualty of a downturn. Despite all the efforts to measure its effectiveness, its rate of return is still questioned in many organisations. However, effective marketing can often be the key to survival in a recession.

Second, organisations must continue to innovate and not be intimidated by bad economic news. Consumers quickly notice who is behind the curve and punish those who cannot keep up with the pace of change.

Our experience tells us two things: it is still important to invest in R&D, even during a recession; and companies must focus on marketing new products to their existing customer base.

Customers need a compelling reason to spend money in the downturn and it is vital that they stay loyal when the market picks up.

Alan Leaman is chief executive of the Management Consultancies Association

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive