In March, Vittorio Colao whisked his children off to Rome for five days.

“It is something that every father should do in life,” said the Italian chief executive of Vodafone, the mobile-phone giant.

Unfortunately, he could not leave work behind completely. From the top of the Vittoriano — the marble monument that honours Victor Emmanuel, the first king of a unified Italy — Colao hosted a conference call on his BlackBerry while looking out on the magnificent views across the Eternal City. His two children, meanwhile, went to get an ice-cream.

“That was really fitting the stereotype,” Colao said with a chuckle, observing that he wouldn’t be the last boss to call into the office while on holiday. But it was when he toured the sites later that he was surprised to see so many tourists at the Colosseum, the Vatican and the Trevi fountain scrutinising maps on their phones or taking pictures. Technology, he noted, was changing their habits.

“Some of them were with the guide who was holding the little umbrella but following a map on their phone as well,” he said. The smartphones that Vodafone had been selling for five years or more to business customers had finally permeated into the mainstream.

The technology revolution is changing everyday behaviour and is about to change Vodafone. This month the company is shaking up its global brand — its biggest overhaul in almost five years.

After a year’s work, out goes the “Make the most of now” tagline, in favour of the simpler “Power to you”. Instead of dictating to customers, Vodafone wants to let them know that they, with phone in hand hooked up to the mobile internet, are now in charge.

For Colao, this is more than just a new marketing push. He has put polishing the company’s brand and image, internally and externally, at the top of his in-tray. “The centre of this company is marketing and human resources,” he said. “It is not the brand talking any more and telling the customer what to do. It is the customer who will decide.”

Colao showed his priorities last month by moving its headquarters from Newbury in Berkshire to Paddington, west London, putting his top executives alongside his marketing team, while the finance unit stayed in Newbury. Vodafone also drafted in Wendy Becker from Carphone Warehouse as chief marketing officer.

“It is not the big power,” said Colao of his new brand identity. “It is not the power of top down. It is bottom-up power. It really means that Vodafone puts the customer at the centre of what we do.”

The rise of smartphones — handsets with the power and usability of personal computers — is a bright spot for an industry that had got used to endless growth. In the last quarter, Vodafone’s service revenues fell 2.1%, or by 4.4% in Europe, where regulatory cuts took their toll and corporate customers tightened up on spending.

As well as cutting costs, Colao must find new revenue streams from software applications that can be downloaded to handsets — another way of “empowering” customers.

Another challenge is loyalty. Some 18% of its better value contract customers quit in the past year. They cost £350 each to recruit. But Colao wants to go beyond mere loyalty to advocacy. “I want my customers to say: ‘You should try Vodafone’,” he said. Instead of merely competing with rival phone brands, that also means seeing how the brand measures up against the likes of Tesco and BMW.

Eight years ago, former boss Sir Chris Gent launched Vodafone’s first global ad campaign, the first step in looping together the federation of companies that he had assembled.

Out went brands such as Omnitel and Airtel. In came the tagline “How Are You?”, the Vodafone brand and red speech mark logo. In the accompanying ad campaign, David Beckham and Michael Schumacher — role models from Vodafone’s sponsorship of Manchester United and Formula One team Ferrari — were seen fooling round with camera phones.

Just as he had done to build the company, Gent threw money at marketing, boasting that Vodafone would be in the top three brand advertisers in each market where it was launched.

It had a lot to live up to. Orange had redefined mobiles as lifestyle accessories with the airy aspiration of “The Future’s Bright, The Future’s Orange”.

Four years later, Vodafone changed tack, instructing customers to “Make the most of now”. “It was a strong international brand with the authority to tell people what to do,” said Colao. “The message was: times are good, now is good, make the most of it.”

This time, at least in Britain, it was O2, once the weakling of the big three operators, that had become the one to beat.

Colao’s predecessor, Arun Sarin, once proclaimed he wanted Vodafone to become the Coca-Cola of mobile phones. But that ambition to create a global brand was seen as dangerous by investors whose alarm at the company’s “bigger is better” strategy finally put the brakes on its dealmaking.

Experts say the latest flurry of activity seeks to mask a deeper concern. Despite pouring millions into advertising every year and sponsoring everything from Champions League football to English cricket, Vodafone’s brand has long suffered from being safe instead of sexy.

Although it has had remarkable success in new markets such as India, the challenge it faces is most sharply drawn in its home market where the company has lagged behind arch rival O2 for the past two years and could now drop into third place after T-Mobile UK and Orange recently announced their merger.

“It has a really big, powerful, muscular brand,” said Rita Clifton, chief executive of Interbrand, the consultancy.

“The consumers need to be able to feel that someone will give them the right coverage on the right network. But Vodafone has struggled with this rather more human connection that other brands have managed.”

Robert Bean, a branding consultant behind the “It’s Good To Talk” campaign while at BT, agreed. “In trying to be all things to all people Vodafone has become ubiquitous, but a blur,” he said.

The threat shows up in UK revenue share, where Vodafone holds 24.7%, behind O2’s 27.7%. Colao, who has campaigned for consolidation in the most overcrowded markets, tried to sound relaxed. “There is no obsession with size,” he said. “I wouldn’t like to be a small player but we are big in the UK. We have critical mass.”

Vodafone bid almost £3.5 billion for T-Mobile but would not go higher. “No regrets, I would say,” added Colao. He still covets the top spot, but will concentrate on becoming the most profitable operator in the UK.

As newspaper publishers try to work out how they can make their business pay in a digital world, Colao believes he has the answer — in part by Vodafone becoming a virtual kiosk that can charge small amounts for small purchases.

“Every day we charge 1 cent, 2 cents for a text messages billions and billions of times,” he said. “Customers trust us to do it in a proper way. We are secure and we have big customer care operations that can deal with problems if they arise.”

This autumn the company will launch an open platform — a service that lets any developer create and sell software applications that can be downloaded to mobiles.

Apple has had a roaring success with its “app store”, selling 65,000 applications from games to travel news more than 1.5 billion times and creating a new revenue stream.

“Apple has done a fantastic job stimulating everyone,” said Colao. “I don’t think [who dominates the market] is going to be black and white. Our focus is on monetisation.”

It does not mean Vodafone has given up on developing. It is close to announcing a suite of online services that will work across mobile and fixed-line internet connections.

For his part, Colao carries five or six phones. Like a walking advertisement, he is using, among others, a BlackBerry, an iPhone, Google’s HTC and a Samsung. He has not heard of anyone who has traded up to a smartphone only to ditch it.

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