Beauty and the brands

When Cheryl Cole burst on to the Los Angeles scene with big hair and purple flares, it was not just US teen temperatures that soared. The pop star, erstwhile X Factorjudge and L'Oréal ambassador, also sparked a 10 per cent surge in global sales of Elnett hairspray, which is made by the French cosmetics company.

In a celebrity-obsessed world, footballers (and their wives), talk show hosts (and their mums: step forward Vernon Kay's mother, Gladys) as well as countless pop stars, actors, models and reality stars have been recruited to sell everything from fizzy drinks to frocks, boxer shorts to margarine.

Consumer goods advertisers' long love-in with celebrities sometimes features the same celebrity over the course of their career. Take Twiggy, the doe-eyed 1960s model who advertised Procter & Gamble's moisturiser, Oil of Ulay (now called Oil of Olay) in 1985 - and again last year, before the airbrushed pictures were banned by the UK's advertising watchdog.

But when it comes to using stars as brand ambassadors, purveyors of consumer goods are refining their own acts.

In earlier days, celebrity advertising was viewed as "a slight cheat; not really advertising but just borrowing [the] equity of someone and trying to hang your product off their coat tails," says Martin Glenn, who as marketing director at Walkers crisps, signed up footballer Gary Lineker.

The longevity of the practice speaks to the fact that it works. According to The Institute of Practitioners in Advertising, J Sainsbury has reaped a return of £27.25 ($44.67)

for every £1 it spent on ads starring Jamie Oliver, the celebrity chef and long-time brand ambassador for the supermarket chain. Global sales of L'Oréal's Casting Crème Gloss rose 200 per cent in three months after Ms Cole used the colourant to turn her hair red.

The desire to shop as celebrities do is virtually global. China, the Philippines and India have joined the trend, but there is a key difference. "Consumers in developed markets are fascinated by celebrities; consumers in developing markets admire them," sums up Marc Mathieu, Unilever's senior vice-president of marketing.

In developed markets, he explains, the use of celebrities is driven by "surprise and attention", which prompts viewers to reassess brands. In emerging markets, by contrast, it is more about consumers wanting to identify with or aspire to look like or even be the face on screen. Diageo's "Words of a journey" campaign in China, a collection of short online films showing entrepreneurs and other celebrities overcoming hardship to achieve their goals, attracted almost 6m visitors within a couple of months of being launched in January.

Global stars, however, can still be used across disparate markets. Footballer David Beckham's face, and more, is plastered around most parts of the world; actor George Clooney has turbocharged sales of Nespresso capsule coffee in Japan and Russia as well as Europe. And, of course, global faces are not all western-born: Chinese singer and actress Fan Bing Bing and Frieda Pinto, star of Slumdog Millionaire, both promote L'Oréal.

But local stars play a role too, as Pierre-Yves Arzel, L'Oréal's managing director for the UK and Ireland explains: "We are an international brand, but want to have local proximity to consumers, so we mix between international faces and local ones."

He highlights another change in recent years: the inclusion of less conventionally glamorous personalities. In February, L'Oréal signed up paralympian, actress and model Aimee Mullins, a double amputee, as a brand ambassador. Next month, the cosmetics group will start running ads featuring Hugh Laurie, British star of the television series House,who Mr Arzel describes as "not the sexiest man on earth".

The key attribute is for the celebrity to "be believable", says Mr Mathieu of Unilever: "So, an actor should act, and a chef should cook." For the Anglo-Dutch consumer goods conglomerate, that translates into advertising its Knorr jelly bouillon in the UK with chef Marco Pierre White and in China with Lin Yilun - a singer by profession and passionate chef by inclination.

This also explains why Walkers, the crisp brand, spurned glamorous pop stars in favour of a footballer who was slightly past his sporting shelf life.

Mr Glenn says: "At the time, Gary Lineker was not a celebrity. He was playing out his career in Japan. He had a bad toe and had not played for ages." However, he had never been booked. "He was the goody-two-shoes of football, so the creative idea was that even Mr Perfect will be tempted [to help himself to other people's packets of Walkers crisps]."

Another credible match is Nestlé's Nespresso and actor George Clooney. "He's a worldwide citizen, a democrat [and] a humanist," enthuses Nespresso chief executive Richard Girardot.

Charlie Rudd, managing director at ad agency BBH, concurs that linking celebrity to brand is the main aim. Bringing in a celebrity is a fast track to getting noticed, he says, but there must be a connection to the brand and the idea behind the campaign.

Heineken knows this to its cost. The Dutch brewer ran a series of ads in 2004 and 2005 using film stars including Jennifer Aniston and, separately, her former husband Brad Pitt. "But he was too central. It was a promotion for Brad Pitt, not Heineken," says Jean-François van Boxmeer, CEO. He concludes that celebrity advertising alone does not work for his brand: "You do that from time to time, but it is absolutely not central to our strategy."

Beyond the potential risk of celebrity brand ambassadors falling from grace (see panel), Hamish Pringle, author of the book Celebrity Sells, points out that consumers are becoming increasingly sophisticated. They may crash websites trying to buy a dress worn by the Duchess of Cambridge, but are rather more sceptical of products that celebrities have been paid to endorse.

"As soon as you move into the area of paid-for [endorsement], cynicism piles in pretty quickly," says Mr Pringle. "Customers look at the combination of product and celebrity and say: 'Does that stack up and make sense?' "

Examples of where the answer is yes include Emporio Armani's use of singer Beyoncé's "bling-bling" credentials in ads for its Diamonds fragrance.

Examples where the answer is no, according to Mr Pringle, include John Cleese and J Sainsbury. Mr Cleese, a gawky British actor best known for playing the accident-prone protagonist of 1970s sitcom Fawlty Towers, was supposed to shout about value. But, says Mr Pringle, the megaphone-wielding character he played in the ads was the antithesis of the "well-spoken, middle-class" supermarket.

There is another kind of celebrity that helps brands too - that of the celebrity CEO. They bring benefits that stretch far beyond mere sales. As Mr Pringle's book points out, they create a culture that attracts talented staff and their power is a major part of the business's success.

However, that too has its pitfalls, since eventually the celebrity CEO will depart, taking their glamour with them.

Choose a personality that fits the brand. Combining a sexy pop star and rubber gloves would stretch credulity. Buy exclusivity. David Beckham may be aesthetically pleasing and globally recognised, but overexposure means dilution for a brand.

Brand loyalty.Ideally, choose someone who genuinely likes your brand: there were red faces all round when pop star and PepsiCo endorser Britney Spears was seen drinking rival Coca-Cola.

Draw up "scandal clauses".Contracts allowing companies to cancel them following detrimental behaviour are vital. Celebrities can, and do, say or do things that do not enhance brand values: witness golfer Tiger Woods, footballer Wayne Rooney or supermodel Kate Moss.

A recent Ipsos Mori poll found that a quarter of consumers around the world said they would stop buying a product if its celebrity endorser was found to be behaving inappropriately. It also found that the Chinese (66 per cent) worry about this more than the British do (15 per cent).

Have deep wallets. A top-ranking celebrity can command multimillion-dollar pay cheques, and large bills for travel and accommodation on top.

Louise Lucas