The use of well-known figures from the entertainment industry is a tried and tested influence strategy, with about 25 per cent of all advertising featuring this technique. Well-known examples include George Clooney (Nespresso), Patrick Dempsey (L’Oreal), Tiger Woods (Nike), Rihanna (Covergirl), Halle Berry (Revlon), Beyonce (Pepsi), Ellen DeGeneres (American Express), Angelina Jolie (Louis Vuitton), Daniel Craig (Heineken). Celebrity endorsement is also an often-used strategy in politics. During the 2012 presidential campaign, several celebrities, including Bruce Springsteen, Beyonce, rapper Jay-Z and George Clooney, came out in support of Barack Obama. During the United Kingdom general election in 2015, several celebrities, including Sol Campbell, Andrew Lloyd Webber, Martin Freeman, Eddie Izzard, Patrick Stewart, John Cleese and many others, joined in to endorse one of the campaigning parties.
Various studies have shown that the technique can indeed have a positive effect on both attitudes towards the brand and actual sales figures (Keel & Nataraajan, 2012). One study, for example, calculated that, as a result of endorsements by Tiger Woods, Nike has sold 103 million dollars’ worth in additional golf balls in the United States alone (Chung, Derdenger & Srinivasan, 2013).
Research identifies two main factors that determine the effectiveness of celebrity endorsements: likeability and congruence. The more likeable a celebrity is, the more positive the impact of their endorsements. They must have some connection with the product, though, otherwise the audience is inclined to regard them as just a moneygrubber, willing to sell their services to anyone prepared to pay (see, for example, Fleck, Korchia & Le Roy, 2012). When the celebrity has some connection to the service or product, such as with Tiger Woods and golf balls, the influence message also obtains additional persuasive influence through the previously discussed effect of expertise. There are also potential risks in celebrity endorsements. A celebrity is always in the spotlight, with their every action scrutinised. When public admiration evaporates or, worse, turns into contempt, this can have disastrous consequences for the party or brand involved. An advertisement for Nike featuring Tiger Woods with the caption ‘Winning takes care of everything’ sparked a storm of protest on social media. Many considered the slogan tasteless and disrespectful in the wake of the extramarital escapades that had cost Woods his marriage in 2010. Erdogan (1999) provides a good overview of the dangers, as well as exploring ways in which advertising agencies and their clients can protect themselves against the potential down sides of celebrity endorsement. Interested readers are also referred to a special issue of the scientific journal Psychology & Marketing (September 2012) on the influence of celebrity endorsement.