Whether out of genuine altruism or just good PR, celebrities frequently become involved with charities and causes. 

The question is, who gets the benefit – the charity or the celebrity? And who is getting it right?

In the case of the partnership between United Nations (UN) Women and its Goodwill Ambassador, young British actor Emma Watson, it’s very much a win-win situation.

In her HeForShe speech at the UN headquarters in New York in September 2014 Ms Watson spoke out against the labelling of feminism as a dirty word.

Her speech gained global media coverage and quickly went viral across the web. Importantly, it wasn’t a one-off. She has continued her campaign for gender equality.

In January (2015) Ms Watson appeared with several world leaders at the annual World Economic Forum in Davos and later undertook a Twitter session where she responded to the public’s tweets regarding feminism.

Again, her response to one tweet went viral and gave the HeForShe cause and UN Women the kind of international exposure PR companies can only dream of. Ms Watson’s intelligent, sincere and polished performances at the UN and Davos have also given her own profile a considerable lift in the process.

We’ve also become familiar with the highly effective role Angelina Jolie has played as a UN Goodwill Ambassador, conducting more than 40 field visits over the last decade and gaining much media attention in the process. Before her there was Audrey Hepburn for UNICEF.

However many people who work in the charity sector will tell you (off the record) that passionate and powerful ambassadors like these three women are hard to come by.

Many celebrities enjoy the title or association that comes with forming a link with a great cause or charity but apart from appearing at the announcement or launch aren’t so willing when it comes to the workload and other expectations.

And there are other challenges facing the celebrity equals success formula. 

Firstly, does the celebrity align with the charity?

Many charities choose only celebrities that have a direct connection with the cause. However this can limit choices.

Could the celebrity bring the charity into disrepute? 

One of the more infamous examples recently was the Grant Hackett incident which not only saw the former Olympian experience his own fall from grace, but also saw him potentially damage the charity for which he was an ambassador.

In 2012 the Herald Sun ran the story “Olympic swim star Grant Hackett has been dumped as ambassador of a major children's charity in the wake of an alcohol-fuelled meltdown. The Allanah and Madeline Foundation, which aims to protect children from violence, last week informed Hackett's management they were cutting ties with the swim star, before the shocking photos emerged in today’s Sunday Herald Sun. 

The celebrity’s association with the Charity damages both the Charity and, in the public eye, makes his own behaviour much worse, further damaging his reputation.

Sometimes the smaller, less well known charities simply don’t have the profile (or cash) to attract an A-list celebrity. 

Sometimes the perfect celebrity for a particular cause is already contracted to another charity and may not be permitted to be identified with another cause.

However while some may argue the equation does not add up, if the strategy is sound and the celebrity can be obtained, it is a winning formula.

For charities that can bring on board A-listers who are not only passionate but intellectual the influence these celebrities can bring is enormous. 

Choosing the right ambassador goes deeper than value alignment and celebrity status. Emma Watson is successful for UN Women for a variety of reasons: she is an intellectual (studying at Brown University and Oxford University); she is a woman and a feminist; she is well liked by most demographics and both sexes; and she falls within an age bracket where social media appeals to her biggest fans. 

While the points in Ms Watson’s UN speech were not new, they were revolutionary to a whole new audience that would not have otherwise engaged in the issue of feminism and equality. 

Getting a charity’s message out beyond the ‘converted’ means real growth, support and eventually change. That is the ultimate success of a celebrity-charity alignment.