For some, it's a calling. For others, it's an opportunity to take their advertising and marketing skills into entirely new territories.
Often, there's the added bonus of the learning that comes from facing a different set of challenges and overcoming them.
Sometimes there's the networking opportunities that arise from encountering people no marcoms executive is ever likely to meet during their working day.
From charities, to theatres, to official bodies that encourage international companies to do more business in London. All are looking to take advantage of the agile thinking and problem-solving that's part of day-to-day agency life.
Those from the industry who choose to take on such extracurricular activities do so for all sorts of reasons. Phil Georgiadis, the Walker Media chairman, is working with Great Ormond Street Children's Hospital to repay his gratitude for a successful life-saving operation on his son; Kate Robertson, the Euro RSCG UK group chairman, has helped found a charity that reflects her conviction that advertising can be used to create a better world.
And Bill Muirhead doesn't rule out turning his part-time job as South Australia's agent-general in London into a full-time one when he eventually steps down as an M&C Saatchi partner.
Sometimes, such roles offer the chance to take a personal interest or passion a significant step further. Tamara Ingram, the president of WPP's Team P&G, is London born-and-bred and is eager to aid its economic prosperity; Farah Ramzan Golant, the Abbott Mead Vickers BBDO chief executive, loves the arts and is involved in broadening the National Theatre's appeal.
Despite offering either no material rewards or just nominal sums, jobs such as these can turn out to be unexpectedly time-consuming. That's particularly true when the position calls for financial nous coupled with astute management skills.
As the non-executive chairman of BBC Children In Need, Stevie Spring, Future Publishing's chief executive, and her fellow trustees oversee the distribution of millions of pounds to hundreds of worthy projects every year. "It's good for people like us to be giving something back," she says. "And you learn so much."
BILL MUIRHEAD, PARTNER, M&C SAATCHI
Agent-General for South Australia
Bill Muirhead is half-adman and half-diplomat, with just a ten-minute walk between the M&C Saatchi office in Golden Square and the Australian High Commission in the Strand separating his two lives.
Not only is Muirhead one of the agency's founding partners, he's also been the London-based agent-general for South Australia in Europe for the past two years.
The job is a demanding and multifaceted one - helping stimulate South Australian imports into Europe and Russia, encouraging European investment in South Australia and boosting the number of skilled workers from the continent settling in the state and more European tourists visiting it.
Muirhead is the first to admit the job isn't without its perks. For one thing, it's salaried. For another, he gets a diplomatic passport. If that's not enough, he doesn't have to pay council tax on his main home or VAT if he buys a new car. Not that he needs to since the post comes complete with a BMW 3 Series and a flag to fly on it.
As befits somebody famed for his top-level contacts, Muirhead, born in South Australia's capital, Adelaide, reports directly to the state's premier, Mike Rann. "It's a great job for networking," Muirhead acknowledges. "I get to see so many people that I wouldn't ordinarily meet."
However, he's aware there's a line to be drawn and that M&C Saatchi could never formally handle any advertising for the state. That hasn't stopped him paying some of the agency's creatives in South Australian wine for some Evening Standard ads, one of which declared: "Screw working in Staines."
"The mayor of Staines went mad, which was enough to get us on to TV," Muirhead smiles. "For a £23,000 spend, I reckon we got about £1.6 million worth of free PR."
It's not the only example of Muirhead's agency expertise being brought to bear.
"With my experience of the commercial world, I've tried to get the agent-general's office run more like a business," he says. "I think it's healthy for agency people to have outside interests, although for some you need a high level of maturity. I couldn't be agent-general if I was a thirtysomething chief executive."
FARAH RAMZAN GOLANT, CHIEF EXECUTIVE, ABBOTT MEAD VICKERS BBDO
Board Member, National Theatre
When the National Theatre first sounded out Farah Ramzan Golant about joining its board last year, her first instinct was to politely decline. With a family, as well as Britain's biggest agency, to run, she protested that she barely had time to phone her mum, let alone help guide such a cultural powerhouse.
But the NT wasn't easily deterred. The board had ambitious marketing plans that went beyond just putting more bums on seats to developing the theatre's digital expertise to better engage with young people. AMV, in general, and Ramzan Golant, in particular, had the kind of profile NT liked and the know-how it reckoned it needed.
Being a board member isn't exactly gruelling. There's a meeting every eight weeks and the odd strategy away day. Oh, yes, you're also expected to go to the theatre at least once a month. For Ramzan Golant, the role has exposed her to an eclectic range of people - her fellow board members include the playwright Kwame Kwei-Armah and Rachel Lomax, the Bank of England's former deputy governor.
So what does she bring to the party? "I know how ideas solve problems," she says. "So I can listen to the debates, analyse the issues quickly and come up with a number of solutions." And she believes she's personally benefited from the experience. "It's like being in a parallel universe - but every time I come back from it, I feel fresh and re-engaged."
Indeed, Ramzan Golant thinks an NT-type board would benefit AMV. "Because we're heavily involved in running the business, we need people who will ask the challenging questions."
STEVIE SPRING, CHIEF EXECUTIVE, FUTURE PUBLISHING
Non-executive chairman of the trustees, BBC Children In Need
Recently, Stevie Spring has spent time with young Aids sufferers at a mentoring project for socially excluded children and at a halfway house for homeless teenagers.
It's a world away from her full-time job as Future Publishing's chief executive, but an essential prerequisite for her other incarnation as the non-executive chairman of BBC Children In Need.
Although the role carries no salary, last year's appointment of Spring to take it on came only after a rigorous selection process. That's hardly surprising since Children In Need is a major UK charity distributing £100 million to around 1,000 projects in a single year.
It's up to Spring and her fellow trustees to make the final call on where that money is spent, ensuring it all goes to a good cause and that charities know how to apply for Children In Need money. Spring reckons her experience at handling cashflow, her useful list of contacts and ability to make every marketing penny count serve her well. And, as she points out, Pudsey Bear is a brand like any other.
Inevitably, the role is demanding. "I devote more time to it than I'd admit to," she says. "But I don't begrudge a second of it. In fact, I'd encourage as many people as possible from our industry to do pro bono work. It not only helps you do your own job better because you've been exposed to a different set of experiences, but it also makes you realise how privileged you are. It helps keep your feet on the ground."
PHIL GEORGIADIS, CHAIRMAN AND CHIEF EXECUTIVE, WALKER MEDIA
Profile-raiser for Great Ormond Street Children's Hospital
The reaction of Phil Georgiadis when Great Ormond Street's Professor Martin Elliott told him that the life-saving surgery on his baby son had been successful was typical of any parent.
Thankfulness that Toby had been saved, admiration for the medical staff who had kept him alive and an overwhelming desire to repay a perceived debt. "Your natural instinct is to say you'll do anything to help," he says.
Toby, who has Down's Syndrome, had been born three months premature, weighed just three pounds and had a heart the size of a small walnut. Today, he's a happy six-year-old. Meanwhile, his father is drawing on his day-job expertise and his industry contacts to keep his promise.
The start of what Georgiadis calls "giving something back" began at the Down's Syndrome Association, where he enlisted the help of Hurrell Moseley Dawson & Grimmer to produce a Tube poster highlighting the problems of job-seeking adults with Down's Syndrome. The poster featured a picture of one such man, with the caption: "You've been looking at John longer than any employer has." He's also pulled in favours elsewhere to get a TV commercial aired on behalf of the association to help remove the stigma from Down's Syndrome children.
But with Great Ormond Street undergoing a major redevelopment, it was inevitable that Georgiadis would want to make good his vow.
The result is an informal group of like minds that includes some Walker Media staffers along with Graham Fink and Tim Duffy, the executive creative director and the chief executive respectively at M&C Saatchi.
The group's plans are not yet fully formed but Georgiadis says the overall aim is to mirror the hospital's famous "Wishing Well" appeal and provide a platform that will keep it front of mind, without the perpetual support of a heavyweight media campaign.
"If it takes six months, it doesn't matter," Georgiadis says. "Getting it right is much more important than rushing out an ad."
TAMARA INGRAM, PRESIDENT OF WPP'S TEAM P&G
Chairman, Visit London; board member, Visit Britain; non-executive director, Sage; board member, Almeida Theatre
Given the range and number of her outside interests, you'd be forgiven for thinking that Tamara Ingram has either been cloned or survives on five seconds sleep a night.
She claims it isn't quite like that because each of these roles has their peaks and troughs. "How much time it takes is hard to say," she explains. "The simple answer is that I give the time as and when it's needed."
What makes it easier is that her involvement in projects such as Visit London, which promotes the capital to tourists - there are 26 million of them a year - and businesses, feeds her passion. "I'm a Londoner, who loves my city," she says. "I see it as a great privilege to be doing something that will help deliver economic benefit to it."
Ingram believes her agency background has been invaluable in helping evolve what was an internally focused London Development Agency into the marketing-led operation that is Visit London. "We, in advertising, devote our working lives to solving problems and building brands," she points out. "We're useful not just because of our marketing expertise but because we know how to set a vision and direction for our clients and we have the people skills. That's very important in an organisation like Visit London where we have so many stakeholders that we need to carry with us."
Ingram is paid a nominal fee for working with Visit London, but rather more as a non-executive director of Sage, the global supplier of business management software. "Being part of a highly qualified team from many backgrounds dealing with complex business issues within a FTSE 100 company is very stimulating," she says.
"What's more, it gives me experience that I can bring to the day job."
Slotted between all this is her membership of the board of Islington's Almeida Theatre. "It's a wonderful place and the job gives me huge personal fulfilment."
KATE ROBERTSON, UK GROUP CHAIRMAN, EURO RSCG
Co-founder, One Young World; non-executive director, YouGovStone
One Young World is Kate Robertson's all-consuming passion and a vehicle she hopes will help move advertising beyond just selling stuff to becoming a force for the greater good.
It sounds idealistic and, yet, it's very much in tune with the thinking of David Jones, the Euro RSCG Worldwide chief executive. Jones is convinced advertising can be used to force the hands of governments across the world to act on big issues such as climate change.
Now the pair have established One Young World with the support of Kofi Annan, Archbishop Desmond Tutu and Bob Geldof. It recognises that young people will be the catalysts for change and will attempt to identify the future leaders capable of achieving it.
It will take the form of annual summits - the first to be held in London next February - where 1,500 young people representing every country in the world will debate global problems and how to solve them. All will have to find sponsors and raise the 23,000 needed to fund their travel and accommodation.
It's been a huge learning curve. "I didn't even know how to register a charity," Robertson confesses.
Nevertheless, she's certain her industry background has stood her in good stead for overcoming such hurdles. "People in our industry are comfortable going into new areas because they learn very fast. What's more, we never give up. We always want to solve problems."
Indeed, it was the problem of how to get to the likes of Geldof and Tutu that led her to Carole Stone, a business consultant, a former producer of the BBC's Any Questions and the owner of a contacts book to die for.
As a result, Robertson now serves as a non-executive director of YouGovStone, a joint venture between YouGov and Stone, that canvasses people's views on a variety of issues. "I bring some commercial nous to what she's trying to do," Robertson says.