Flickr. Cisco Systems. DKNY. These are just some of the world's most successful businesses that have been started by husband-and-wife teams.
There are three million family-run firms in the UK and it is thought around a third of these are run by spouses. Of the successful ones, couples say their complementary personalities and skill sets make them ideal business partners.
But they are the lucky ones. The pressure of running a business and a home together can end in disaster. Take David and Elizabeth Emanuel, the former husband-and-wife design team that created Diana, Princess of Wales's wedding dress. The pair split in 1990 and were later embroiled in a bitter divorce after their label ran into financial trouble. They still ignore each other at public events and, to this day, bicker over who took 'that' call from Diana in 1981.
Or look at Amancio Ortega and Rosalia Mera, the Spanish duo behind Inditex (owner of Zara). They started by making dressing gowns in their living room in the 1970s but as their business grew, their marriage came under strain, with Ortega allegedly fathering another child with an Inditex employee. They divorced in 1986. Another not-so-happy ending.
Sarah Curran, one of MT's 35 Women Under 35 2008, set up my-wardrobe.com eight years ago with her husband, saying they felt 'almost invincible' as a team. They, too, split: 'When you take away that half and you're on your own, it's difficult,' she has said. Curran left the business last July and my-wardrobe was later sold in a pre-pack administration deal in November.
Denise Knowles, a relationship counsellor at advice service Relate, says: 'While working together and having shared goals can help couples feel closer, for some people it can become too intense, especially if the individuals approach work differently or if the business causes stress in the relationship.'
So what's the formula for business success with your spouse? How do you cope when your dates are spent chained to your BlackBerry and your pillow talk is profits? We spoke to four couples who have made it work, for better or worse, to find out.
MR & MRS SMITH
James Lohan and Tamara Heber-Percy
I'm certain we talk and think about work far more than other married couples. It's an obsession - or a curse - for both of us,' says James Lohan, one half of Mr & Mrs Smith, the boutique-hotel booking site. 'We have one proper day off a year, Christmas Day.'
'It's relentless,' agrees Tamara Heber-Percy. 'We're in the travel business so even when we go away, we're on show, we're taking notes. We're always Mr & Mrs Smith.'
But the punishing schedule hasn't taken its toll on their relationship. The couple, who met in 1997 and married in 2006, struggle to think of a single thing that annoys them about each other. They never argue, apparently. Hell, they even lived on a boat.
'Of course, there are dark moments - we've woken in the night wondering if we'll make payroll; the guilt of missing out on our children, Alexandra and Tom - but running a business together has made us stronger,' says Heber-Percy (or Tam, as Lohan affectionately calls her). 'I get to see a professional side to James that most wives never see. I'll watch him turn on his charm in a meeting and think, he's pretty sexy!'
The pair started Mr & Mrs Smith as a hobby in 2002 after a 'disastrous weekend away' and have turned it into a global business employing 100 people. The company has 850,000 members worldwide and will take £40m in hotel bookings this year.
They've based their office in Chiswick, five minutes from their home and 20 minutes from Heathrow. Heber-Percy says she likes to be near the children. Lohan says he hasn't once missed a school play or a sports day: 'My dad missed out on those things with me. I want our children to know that although their dad works his butt off, he's always around.'
The growth of the business - particularly its expansion into overseas markets - has brought its own challenges. Heber-Percy says she puts the kids to bed then spends the evenings answering emails from New York; she then wakes up to 100-plus messages from the Melbourne office.
'You suddenly go from a small, entrepreneurial company, where everyone mucks in, to a grown-up business with an office manager and a board,' says Lohan. 'That can be stifling. There are times when we've felt trapped.'
The couple want to sell up eventually. For both of them, it's all or nothing. 'I can't imagine being married to a stay-at-home wife who didn't understand the pressures of the business. We'd be living two separate lives,' says Lohan. 'Even if Tam was doing a two or three-day week, it would wreck our balance. We're level and equal on everything. We're in it together and we'll leave it together.'
Marriage saver: Make sure you have different roles so you don't tread on each other's toes. James looks after the brand while Tamara deals with the technology.
Marriage wrecker: Putting in different hours. If one of you does more in the office and the other does more at home, it'll cause resentment.
Adam Twidell and Carol Cork
Adam Twidell and Carol Cork remember the moment they nearly cracked. It was the summer of 2009. The couple and their two children, Grace and Angus, were holidaying in a farmhouse in Italy with four other families. 'It should have been a relaxing break but it was the complete opposite,' recalls Twidell, a former RAF pilot. 'Carol and I were glued to our laptops the entire time; our business was monopolising our lives. We had to ask our friends to entertain our kids. It had reached the point of ridiculous.'
The pair had started PrivateFly - a price-comparison site for private jet travel - three years earlier, selling their house to fund the software development. 'Industry experts thought the idea would never fly; they said no one would book a private jet flight online,' says Twidell. 'But by 2008 we'd launched the site and were taking bookings.'
With success came stress. 'We tried to do everything ourselves and it ended up encroaching on every second of our spare time,' says Cork. 'On the way back from Italy, we decided "enough", we needed help. In retrospect, we were crazy to wait that long to hire other people.
It immediately relieved the pressure and it forced us to behave more professionally towards each other.
When it's just the two of you cooped up in a room, you can be as rude as you like!'
Twidell and Cork, who have been married for 12 years, now employ 15 staff and will turn over £11m this year. They've based the PrivateFly office in St Albans in Hertfordshire, close to where they live and 20 minutes from their children's school.
Twidell says they treat the business like a third child. 'We always talk about PrivateFly at home and involve the kids. During half-term, Grace came into the office and spent an hour vacuuming and shredding. It's a family firm so we've tried to create a family- friendly environment.'
'We have a great nanny who holds everything together,' adds Cork. 'I do feel guilty but show me a working mother who doesn't.'
Twidell heads operations, while Cork runs the sales and marketing. He's the risk taker; she's the realist. When there's a difference of opinion over the business, they'll turn to Vicky Skeat, PrivateFly's head of finance, for a balanced view but, ultimately, it's Adam who calls the shots: 'In any husband-and-wife team, there can only really be one boss,' says Cork. 'In the end, someone has to have the casting vote.'
Marriage saver: Make your business part of the family. Think of it as one of your children.
Marriage wrecker: Never travel to work together. 'Even if we arrive at the office together, I'll walk in a few minutes ahead of Carol,' says Adam.
'It's important to have that transition time.'
Rob Baines and Pablo Uribe
Rob Baines and Pablo Uribe met at a dinner party 17 years ago and the two have been an item, and worked together, ever since. Uribe had come to London from Colombia to do a master's in architecture, and after he finished the two set up an architecture practice together and later a coffee shop in Fulham called Tinto. 'There was never any fear in our working together. My parents did, so that's what I grew up with,' says Uribe.
Vancouver-born Baines, who moved to London more than two decades ago, started in investment banking before moving into the food and drink business. The pair came up with the idea for Snog after seeing how popular frozen yoghurt was in the US, but noticing that it was full of sugar. They designed a healthier alternative, Snog, which uses organic yoghurt and agave nectar as a sweetener.
Starting with one shop in South Kensington, they now own nine stores across London and the south-east, and pots of the yoghurt can now be bought in over 3,000 UK stores after Unilever invested in the firm in 2012.
Uribe takes care of Snog's brand and store design - each outlet is unique and inspired by Japanese pop art with a pink twist - while Baines takes care of the numbers.
When not working, the pair live, socialise, travel and work out together.
They live in Soho, next to their HQ, but they also own homes in Rio de Janeiro, the Hamptons, New York, Colombia and Ibiza. The gluten-free fitness fanatics don't drink or smoke. When asked how they celebrated the Unilever deal, they said they didn't do anything special. 'We have such an amazing life that really every day is a celebration,' Uribe explains.
A typical weekend will involve walking their miniature dachshund, Milo, in St James's Park, followed by a swim or a session in the gym and a trip to the cinema or dinner with friends. Every other weekend they might visit their home in Ibiza, or go travelling elsewhere.
'Aside from meetings, all our work can be done over email. So you can be anywhere in the world. It's really important for us to be exposed to all of the world's trends. That's why we travel so much - so we are able to bring such a fresh perspective to our stores,' says Baines.
When in London, they don't have meetings before 11am to give them time to meditate, answer emails and work out. 'A lot of couples stress about finances, but we've never fought about money because our goal wasn't to make lots of money,' Baines says.
They find it hard to switch off from the business, and bounce ideas around day and night.
How do they cope if things get heated? 'It sounds naff but don't go to bed pissed off with each other,' Uribe adds. 'Deal with what you need to deal with and don't let resentments build up.'
Relationship saver: Don't get stressed. When you've worked together for so long, you know that everything will turn out all right in the end.
Relationship wrecker: Don't let egos get in the way of decisions. Make sure there are no power games and always find a common sense solution.
Edwina Dunn and Clive Humby
Edwina Dunn and Clive Humby met on the first day of her first job at US data firm CACI. They got together a year later and were married within seven months. For nine years, they both carried on working at CACI before Humby left to set up his own business. The couple had just taken out a huge mortgage, but disaster struck when Dunn was fired straight after, with CACI citing a conflict of interest.
With money tight, Dunn and Humby drew up a 10-year plan for a data-mining company. They worked in the back bedroom of their house in Chiswick before moving into a tiny office nearby. Their daughter Rowena was born 18 months after Dunnhumby was created and a son, Max, arrived a couple of years later. 'We always had a full-time nanny even though we couldn't afford one,' Dunn says. 'We didn't pay ourselves anything for two years.'
'At the beginning, Eddy probably had more time at home with the kids,' Humby adds. 'But, as the business went international to 30 countries and we grew to 1,500 employees, the roles reversed and I was at home more. She focused on marketing and I was more of a techie.'
The turning point came when Tesco approached them in 1995 for help with boosting loyalty, and the Clubcard was born.
As the firm took off, the couple made sure business didn't take over their life. They had a strict rule at home: never to talk about business in any room other than the home office.
They don't do long hours and tend not to work weekends. Of the two, Dunn is more organised so they never travel to work together. 'We used to fall out waiting for each other. I think people are quite grumpy first thing. We found very early on it was a point of irritation,' Dunn says.
The pair have never had a major disagreement, they say. Their lowest point was when CACI sued them after they won their first contract. 'That was brutal. We had nights of no sleep. There was a moment when we had to look at each other and ask if we lost everything, could we start again? That's very bonding,' Dunn says. 'But there was no question that we were going to get through it,' Humby adds.
After selling their last stake in Dunnhumby to Tesco in 2011, the couple - worth around £90m - took a year out. They sailed, travelled and spent time in their homes in west London, Gloucester and Mallorca. But it was soon back to work. They now run two companies, Purple Seven and Starcount, analytics firms that specialise in the arts and social media respectively.
'Have we the energy? Not only do we have most of the energy, we have a third business partner. Poor him. It's like being the official gooseberry.'
Marriage saver: Keep work talk to a minimum at home and respect that even if you've had a heavy day your other half may not want to talk about it.
Marriage wrecker: You can't afford to shout at each other. Working partners can shout a bit more, but when they're your spouse too, you have to listen.