About 45 years ago there was an ad on the London Underground encouraging people to use long-distance rail for meetings. It had a sell line which must have stuck in many people’s minds. Over a photo of a bored-looking business person on the phone, and another of two people looking happy in a meeting, the copy read: “It’s the difference between hearing what you say... and seeing what you mean.”

Back then the telephone was a relatively new invention and long-distance calling had only recently become affordable to non-millionaires. So the ad was trying to encourage people back to the more human, visceral virtues of an old-school, face-to-face interaction.

At about the same time, AT&T in the US was bringing to market a spectacular way of reviving the pleasures and benefits of meeting as opposed to phoning.

These days, AT&T’s solution to the problem of impersonal, tinny voice-only business powwows would have been sold as ‘green’, on the grounds that they didn’t involve flying or driving. But back then it was more about convenience, cost saving and the sheer joy of futuristic technology.

AT&T’s contribution to cutting back on business travel was called the Picturephone, a video phone of the type that science-fiction comics had been promising for a decade or more, along with hose-down plastic furniture, flying cars and Lurex spacesuits for all. The company ploughed $1bn into the project, which was launched at the 1964 World’s Fair in New York, with an inaugural call made by Lady Bird Johnson, the first lady.

It subsequently turned into an embarrassing flop. Legend had it that almost the only Picturephone purchaser was Hugh Hefner, who installed the devices, for whatever reason, throughout his Playboy mansion.

One of the problems with the Picturephone for the ordinary consumer was that an ‘early adopter’ would find himself with a device about as useful as one shoe; it was unlikely that you would have many, or any, people to video phone.

But there were other issues, more deep-seated and cultural, which made the Picturephone say: ‘Don’t buy me.’ What, for example, would you do if you were in your underwear when it rang? Would you pick it up, ignore it, or answer it, but turn the camera off and have everybody wonder why you’d done so?

After it was all over, one chastened AT&T executive said: ‘A Picturephone added little to phone conversations and sometimes even got in the way. The acoustical intimacy of a phone call was shattered by the visual imagery.’

Nevertheless, with technology companies being mostly run by sci-fifans still waiting for their flying car, the video phone has kept reappearing for nearly 50 years. There was an enormous launch in the UK and Italy in 2003 by the 3 phone network of a video mobile phone running on the new 3G phone system. Video was widely seen as the future of mobiles, but again was a spectacular failure. Hardly anyone made more than one test call. As it was dying on its feet, the network’s Hong Kong owners suggested that the far-flung Chinese diaspora would love video calling and make the technology succeed. They didn’t, and it didn’t.

In the past year, however, there have been indications that video calling just might finally reach critical mass and become a popular technology.

Initially, the possible boom in uptake was fuelled by improvements in Skype video calls, which were very poor when first introduced, but began to be really vivid and enjoyable, given a good internet connection at both ends.

Then, last year, Apple launched its FaceTime facility for iPhone, iPads and MacBooks. FaceTime offered wide-screen, high-definition calling and was presented by the company as the Next Big Thing. Apple has a great track record in taking existing but unloved technology and making it wildly popular; their 2001 iPod was a repackaged version of existing, but unwanted, mp3 players.

Soon after FaceTime’s launch, Microsoft waded into video calling (as well as voice- only internet phone calls) by buying Skype for $8.5bn – less, proportionately, than AT&T paid for the Picturephone, but still not inconsiderable. Microsoft still hasn’t announced quite what it will do to develop Skype, but it’s odds-on that video calling will be ramped up as part of its offering.

All this has convinced some serious analysts outside Microsoft and Apple that video really has come to stay. Forrester Consulting believes video will “become the new business norm for communication and collaboration over the next five to 10 years” – partly because of technological improvements and partly because the YouTube generation expects everything to be that way.

There’s one big question, though, to worry those piling money into video calling. At the moment, Skype is free to 99% of its 663 million users – just 1% pay for Skype calls to regular phones. FaceTime is completely free, although it requires Apple products at both ends of a call.

So video calling for consumers currently costs nothing. In this light, maybe it’s no wonder that millions of us happily use it for social calls, often for hours at a time. My daughter in New York recently video-tutored me, in London, through a complicated recipe, each with our laptops in the kitchen.

Were the service to be charged for – as it ultimately will have to be, surely – I wonder if we would have done the same? I rather doubt it.