Naked truth about faces that make ads pay off

Paying celebrities vast amounts of money to endorse products can reap huge dividends. And if the latest figures are to be believed,Jamie Oliver and Gary Lineker are entitled to ask Sainsbury's and Walkers crisps for pay rises.

Considering that the television chef Oliver is estimated to have generated almost half of Sainsbury's profits of £535m over the past two years, even his mother Sally, who appears in some of the commercials, might be entitled to a little extra. And Sainsbury's really ought to turn a blind eye if his wife, Jules, is seen again carrying shopping from one of its rivals.

The earning power of Oliver and Lineker has been analysed in research for both companies and shows the proportion of profits directly attributable to the advertising in which they feature, making them among the most successful such campaigns.

Oliver's bloky adverts are estimated to have netted £200m profits in the past two years. The campaign cost £41m, but generated an extra £1.12bn in turnover, a return of £27.25 for every pound spent on advertising. Sainsbury's say it is 65 per cent more effective than previous campaigns.

Sainsbury's refuses to say how much Oliver is paid, but reports suggest it is about£1m a year. The relationship has not been without its ups and downs – Oliver was reported to have criticised some Sainsbury's products and admitted he did not use them in his restaurants.

Gary Lineker's commercials for Walkers crisps, trading on his image as football's "Mr Nice Guy" by portraying him in mean-spirited roles, are estimated to have increased sales by £60m. Walkers says the campaign has led to an extra 112 million packets being sold over the past two years.

Unsurprisingly, Lineker is also reported to be on a five-year contract of more than £1.5m, far better job security than most football managers can find.

The figures have been disclosed in submissions by the two companies and their advertising agency, Abbott Mead Vickers BBDO, Britain's largest, to the annual Effectiveness Awards run by the Institute of Practitioners in Advertising. Both campaigns received silver awards.

The research, using independent testing, eliminates other factors such as store refurbishments, in the case of Sainsbury's or package design for Walkers.

Bridget Angear, planning director of the agency, is naturally enthusiastic about celebrity-led campaigns, but is also aware of the pitfalls. In 1995 Sainsbury's used John Cleese to front a campaign. "We got the wrong tone of voice. One ad had Cleese shouting at a member of staff. Sainsbury's has more than 140,000 employees, and those are the last people you want to offend.'' It was swiftly dropped.

The England football manager, Sven Goran Eriksson, was also used by Sainsbury's earlier this year when his star and England's footballing hopes were high. His tangled private life and the team's lack of success make him a less likely option now.

The awards showed how celebrities can be used in a worthy cause. The award for insight and innovation went to M&C Saatchi for the first national Home Office police recruitment campaign, which featured Lennox Lewis and Bob Geldof. The campaign substantially boosted recruitment.

But the top award went to a campaign entirely devoid of either celebrities or humour. Bartle Bogle and Hegarty's advertisements for Barnardo's, which featured heroin- injecting babies and alcoholic children, resulted in an increase of £46m in income for the charity over the 29 months in which the campaign ran.