Then he beams a beatific smile. For if work is a football game — Fuller is allowed to be obsessive because he was once on Newcastle FC’s books — then he is about to go in at half-time, having just banged in an equaliser in a match in which his team was taking a pasting.

Last Thursday’s confirmation that 3 has passed the 1m UK customer mark is a kick on the shins for those who predicted that its third-generation (3G) network was going nowhere fast. It is also an affirmation of Fuller’s skills as an experienced organiser and motivator.

His network put on 270,000 subscribers in July alone, making 3 Britain’s fastest-growing phone company. And while he has achieved this by offering extraordinarily low tariffs and heavily subsidised handsets, at least he has got people using 3 and taking it seriously. After last year’s difficult start — unreliable service, unavailable handsets, unappealing marketing — that’s half the battle.

Fuller, an accountant-turned-tech boss who was shipped in by 3’s owner, Hutchison Whampoa, three months after 3 launched, is keen to play down those teething troubles. “We’ve never had a problem with demand,” he says, sitting in the London offices of 3’s PR adviser. “The issue was always the shortage of handsets.”

Then, a minute later, he says that the issue was also communication. “We hadn’t really sorted out our marketing entry strategy.”

And perhaps it was the service’s content, too. “When we launched, we had the phone as the portal up there and we thought consumers would use it, but just because you put something on a handset doesn’t mean customers buy it. Now we’re getting better at selling things to them.”

So changes all round, with 3, understandably, learning as it goes along, providing the country’s first 3G service (videocalls, television news, goals as they’re scored, direct to your handset) well in advance of the established mobile networks.

And that’s the nub of the gamble taken by Hutchison, the shops, ports and telecoms conglomerate run by Hong Kong billionaire Li Ka-shing. Get in first, grab a chunk of the market before the others — now making a mint from 2G — have launched their own alternatives.

Hutchison is doing it in a clutch of countries across the world, having sold its interest in Orange to back the bet with an estimated £11 billion investment. In Hong Kong, they enjoy their gambling.

And in Fuller, 57, a chunky, silver-haired Geordie who likes to keep things simple, they seem to have found the right man to give 3 a human feel. It was Fuller and his No 2, Gareth Jones, both Orange veterans, who commissioned the eye-catching commercials for 3 featuring the actress Anna Friel lounging in a bath or swimming in a pool.

“We were trying to move away from being a technology-orientated brand,” says Fuller, “into something warmer and more personal, and she comes across as a bit cheeky and a bit provocative. It tells people there’s something new here.”

Not just about getting sad, middle-aged men interested? “I dunno,” says Fuller. “Did it work?” Then he cackles with laughter. Fuller was a professional footballer ( “No 9, bit of a tradition at Newcastle”) in the 1960s before stints at the National Coal Board and British Gas turned him into a manager, and he retains that populist touch. Jargon is avoided, propositions stripped to basics, plain English spoken with that Geordie lilt — he epitomises the current trend for tech bosses to be far more customer-friendly than their non-tech counterparts.

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