The naked truth about celebrity endorsements

The pitfalls of the celebrity endorsement were thrown into sharp relief yesterday with the news that two of its brightest (and most expensive) stars do not use the products they advertise.

The pitfalls of the celebrity endorsement were thrown into sharp relief yesterday with the news that two of its brightest (and most expensive) stars do not use the products they advertise.

In the US, a lawsuit filed by a consumer group forced sports giant Nike to admit Tiger Woods does not use the Nike Tour Accuracy golf balls he is paid £694,000 a year to endorse.

In his recent run of victories, he has used a modified ball, created specially for him. The lawsuit, brought by a non-profit organisation called Public Remedies Inc, claims Nike was misleading golfers into thinking they were playing with the same ball as Woods, and demands the company returns its "ill-gotten gains" to the public.

In Britain, Jamie Oliver, the omnipresent Naked Chef who broke a BBC precedent to front a £1m advertising campaign for supermarket chain Sainsbury, has admitted he uses independent suppliers.

"I do not buy from Sainsbury's for my restaurant," he said. "For any chef, supermarkets are like a factory. I buy from specialist growers, organic suppliers and farmers." It was pointed out in Oliver's defence that restaurants do not use supermarkets for supplies, and the adverts show him in a domestic setting.

But Woods and Oliver are not the first celebrities hoist by their own endorsements. Australian spin bowler Shane Warne was caught smoking, after pharmaceutical giant Upjohn and Pharmacia, makers of Nicorette chewing gum, had sponsored him for £84,000 to quit. Actress Helena Bonham Carter was signed as the face of Yardley cosmetics, then admitted she didn't wear makeup.

But, said David Benady, deputy editor of Marketing Week magazine, sponsors should not be surprised. "If you've got a top footballer or pop star they're not always the most dependable. Things can go wrong, and often do."

He cited Pepsi's use of singer Michael Jackson until damaging claims about his sex life came to light. "With Jamie Oliver and Tiger Woods, (the revelations) might not necessarily be bad for business, but it just looks silly. You would expect Jamie Oliver to go to Sainsbury's." In the world of celebrity endorsement, some associations look unlikely, such as Ivana Trump's endorsement of Kentucky Fried Chicken, or the advertising by comedian Jim Davidson, who recently signed a £3.5m two-year deal with the BBC, of a car finance company, under the slogan: "Need a car but can't get credit?"

"With Jim Davidson, you are targeting a certain sector of the population," said Mr Benady. "It won't matter if they aren't going to use the product themselves, it matters that they identify with the brand."

Matthew Patten, chief executive of M&C Saatchi Sponsorship, said: "If you look at sport and entertainment, coverage used to be about the sport, or the entertainment. Now it's all about personalities, which makes endorsement all the more effective."

Savvy marketing men are ensuring their "celebrity"is never likely to misbehave, by using techno-personalities, such as Lara Croft in Lucozade ads, or even dead celebrities, such as those in an ad for After Eights.