"Work and play, they don't get on. But, if you had the tools to get more done on the move, there's really no reason why they shouldn't," Bartle Bogle Hegarty's ad for Vodafone says. Mobile phones, BlackBerrys and greater broadband penetration do indeed mean for some that they can be home for the all-important bath time, but still have time to catch up on their work.
But even with the huge advances in communications technology, for many agency staff, striking any kind of work-life balance would be a luxury.
A life consisting of early morning starts followed by late nights entertaining clients; working through the weekend on pitches and late-night BlackBerry tapping as US bosses demand instant responses is becoming the norm.
Binge-working has become endemic and family life has suffered the consequences.
Jeremy Bowles, a former partner at WCRS, says: "I had three children by the time I was 29, and I didn't see them nearly enough when they were growing up. But I wasn't aware of this fact, as I was so consumed with work."
Working long hours not only undermines personal lives, but can also damage people's health. We have all become familiar with the notion of work-life balance and can understand that overwork can lead to a loss of perspective, exhaustion and, ultimately, professional burn-out.
Judy Mitchem, the chief marketing officer at Lowe London, explains that this kind of lifestyle means agencies are finding it hard to retain their talented staff.
"The sweatshop culture is no longer celebrated," she says. "People won't just work long hours for the sake of it. They want quality of life, recognition and fulfilment. It is not unusual for a talented young account person to resign and go travelling.
They have a far more flexible approach to their careers these days.
"If, like me, you have three children and a nanny who clocks off at 7pm, you need to be out the door. I can never do spontaneous drinks in the pub after work. But I can work late by planning in advance."
Some agencies have formal policies about work-life balance, while for others it is just part of the culture they promote. But, as Christine Walker, the chairman of Walker Media, explains, agencies never force their staff to work long hours. It comes down to a matter of personal choice.
"We now check holiday records to make sure people take time off," she says. "But, at the end of the day, it's in the hands of the individual."
In a service-led industry, long hours are often inevitable. But agencies are beginning to see they have to offer rewards and incentives to retain staff.
Stuart Archibald, a managing partner at Archibald Ingall Stretton, explains: "Agencies, by their nature and culture, are very work-oriented. The challenge for agency partners is how to promote the work-life balance by offering sabbaticals and the option to work from home. Agencies need to give something back and make people want to stay."
Achieving a tolerable work-life balance demands daily juggling, compromise, treats, compensations, wit and a high degree of understanding from both ends of the see-saw. However, ultimately, the people who value family above work will move to agencies that allow them to.
CHAIRMAN - Cilla Snowball, chairman, AMV BBDO and Proximity London
"Work-life balance is a glorious but elusive ambition for most of us. We are ardent supporters, yet all-too-frequent offenders. We are unhappy with the imbalance and we want to fix it.
"It is not just a female and family issue. We all share the problem of time deprivation in a world where the 24/7 culture has replaced nine-to-five. And we are probably all to blame.
"Fixing it means working harder to rectify the imbalance. As employers, by providing a culture that supports and encourages work-life balance.
As employees, by exercising the discipline and expert juggling skills that help us make time for the things and people we love outside work."
FORMER AGENCY PARTNER - Jeremy Bowles, former partner, WCRS
"I think people work as hard as they want to work. The hours fly by if you enjoy what you're doing. But clients should appreciate and acknowledge this to keep agency staff motivated.
"The industry has changed. People aren't paid as well, they work long hours. There isn't as much fun. It used to be a case of an intense period of work that was punctured by a lunch. Most agencies are now run much tighter, teams are much smaller. You have a lot of self-starters, entrepreneurs who have a lot of pride in what they do and want to put in the hours."
MANAGING DIRECTOR - Chris Macdonald, managing director, McCann Erickson
"We work in a service industry, servicing clients' business, delivering against tough deadlines, so we have to work hard.
"The people in our industry are self-motivated, they want to work hard to deliver for their clients.
"I think we are lucky to enjoy socialising with our clients after hours and to like the people we work with.
"If you're smart, you can create a work-life balance. It's all about organising your life and organising your time."
CHAIRMAN - Christine Walker, chairman, Walker Media
"There is substantive evidence that the long working hours demanded by the ad industry can break up your marriage. But this might be equally true if you are a lawyer.
"The attitude of management has changed dramatically. It used to be definitively frowned upon if you went home early. My boss frequently used to work to between 10pm and 11pm at night. Today, I think work-life balance is positively encouraged.
"At the same time, if you want to get on, the ad industry is all about communication, about talking to people, both in and out of office hours. To think you can do a nine-till-five and succeed is naive."