And, of course, given the explosion of reality and internet programming over the past five years, the definition of what constitutes celebrity has expanded to include all manner of individual determined to have their 15 minutes of fame at almost any cost.

As a result, the brand owner’s task of choosing the right celebrity to be an ambassador for their product can be a real minefield. Get it right and your brand will resonate with your consumers, which will translate into sales. Get it wrong and you risk public backlash, alienating your consumer and ultimately the very real challenge of rebuilding that relationship.

One brand that tends to get it right is Channel. The rule they follow is simple – align a beautiful person with a beauty product. Keira Knightley, the current ambassador for Chanel, is young, talented and, of course, beautiful. Chanel, an enduring but nearly 100 year-old brand, uses Knightley to strike a balance between retaining its older, faithful customer base while reaching out to a new youthful audience. Given the cache of the brand, an association with Chanel has been coveted by celebrities for decades as it usually makes for mutually beneficial partnerships.

Too often though, brands look to capitalise on the star of the moment rather than looking for a star who really speaks to their core consumer.  A few years ago US car manufacturer Buick engaged Tiger Woods in a reported $40M deal to endorse their standard family car, targeted at the average, ‘middle of the road’ purchaser. The problem? Golf is a sport still largely played by white collar, executives – a complete mismatch for the blue collar consumer of Buick.

On the flip side, Gillette’s use of Tiger Woods is a much more effective combination of celebrity and product. Gillette essentially ‘upscaled’ Tiger Woods, placing him in a suit and using a city skyline as backdrop. From a consumer perspective, for just a small investment every man could, after each shave, live a little like Woods.

So in an ideal world what celebrity would pair up the best with which brand? For me, a brand able to get the ‘ungettable’ celebrity would win hands down. Some celebrities simply never do brand associations and so, almost by default, they are more attractive to brand owners. Bruce Springsteen, for example, promoting any middle class brand, be it jeans, beer or automotive would be sure to fly.

Similarly Meryl Streep or Helen Mirren would be ideal for high-end endorsements that appeal to a more intellectual or liberal demographic, so aligning with the Volvo or Prius could be a good link.

There are two main risks that a brand runs by involving a celebrity. First, the celebrity may become embroiled in some scandal while under contract which, depending on the brand, may prove fatal to the campaign. Second, the brand owner may misread its consumers and go down the shock value route, which can result in alienation and defection. Brand owners need to understand these risks and manage them carefully through making a considered choice of celebrity partner.

So what does the future hold for celebrity partnerships? We’ve seen a new ‘sub class’ of celebrity reality stars really resonate with the public. In my view, brands that are able to harness these celebrities admittedly short shelf lives by capitalising on whatever that person is known for – be it a cleaning fixation in the Big Brother House or tap dancing on Youtube – will really prosper over the coming years.

David Reeder is the vice president of Greenlight, which is a rights clearance company. Celebrities in its portfolio include Johnny Cash and June Carter Cash, Albert Einstein, Steve McQueen, Mae West, James Cagney, Gloria Swanson and Maria Callas.