In that one performance of I Dreamed a Dream, Susan Boyle, the 48-year-old unkissed Scot, has transformed the nature of television, creating perhaps the world's first global television show.

Since she emerged two weeks ago, ITV has started to take calls from Californians asking whether they may vote on Britain's Got Talent (the answer, miserably, seems to be no). Demi Moore's mere mention of Susan Boyle on her Twitter feed sent one million (yes, one million) people to find Susan Boyle online.

It is not only Britons or Americans who are watching: on YouTube, of the 75 million - and rising - views, about one in six is British and only a slightly higher proportion are American. Far more than half come from the rest of the world. Overseas television rights are held by the show's producers, Simon Cowell and RTL's Fremantle. If they are quick enough, they could probably sell the rest of this series of Britain's Got Talent around the world, which might herald the start of Britain's export-led recovery that Alistair Darling so badly needs.

OK, so that is going a bit far, but while ITV registers audiences of 12 million for the show, one wonders, amid all this hoo-ha, what ratings a globally televised final could get. Already, the Got Talent format has been sold to 27 countries (India is the next big territory coming up; expect to hear some real-life Slumdog stories soon), and so the idea is familar enough, but the brilliantly produced, tear-inducing British version may just be good enough to travel.

Go back to YouTube's all-time charts, and Britain's Got Talent contributes three clips in the top 50. On that basis, it is the most popular television show in the world (there are only two High School Musical clips by contrast); most of the top 50 are music videos of various kinds.

What is also clear is the speed at which audiences are emerging, and what is remarkable about the Boyle phenomenon is how fast she has reached so many people - another reminder, if one were needed, that there is no long tail of occasionally selling content, just a very big head. Success, when it comes, comes quicker and globally, or at least across the English-speaking world, and in greater volumes than before.

Of course, Simon Cowell making more money may not be a route to broader British wealth creation, even at 50 per cent tax, but selling the show worldwide appears to be the only near-term hope for commercially exploiting the success of Susan Boyle until the obligatory CD. Yet, remarkably, ITV and YouTube have failed to reach terms on how to sell advertising around the singing clips, in one of those long-winded “negotiations” that both sides insist is not a row. What is at stake in the Battle of the Boyle - reported on by The Times this week - is not only the £1 million that is failing to be generated via YouTube in the absence of advertising, but the balance of power between a broadcaster and the video-sharing website. Where the boundary falls will help to determine the commercial future of television over the internet.

On the face of it, YouTube might appear to have the better cards. It is global and wildly successful with audiences, but not very successful at generating revenue - it seems too embarrassed to reveal figures. ITV is only a British broadcaster, struggling with a recession, and in need of a new chief executive who might have given more urgency to the YouTube talks before this season of Britain's Got Talent began.

Indeed, for anyone looking for an indictment of Michael Grade's TV-led tenure at ITV, apart from the fall in the share price, this is it.

Yet, not outrageously, ITV thinks that it knows a thing or two about commercial television. It wants to air advertisements as pre-rolls during clips, a format that YouTube, long obsessed by overlay advertising, is only gradually coming round to. If overlay advertising is such a brilliant idea, one wonders why broadcasters don't use it around the world. The key point with television advertising is not whether it is “intrusive” - it is meant to get your attention - but whether there is too much of it.

There are other points too, not least how big YouTube's cut should be for hosting material that it does not produce. But YouTube does contribute a brand that matters to consumers, otherwise the world would head over to ITV.com, which despite a brand name that Apple (home of the small i) would die to own, not enough people do.

Still, when the two sides get there, it will result in a deal that creates an online template for commercial television - how advertisements will be displayed, how many, and what terms will be acceptable.

They ought to get on with it, too, and not just because both could do with a windfall. The day is coming, perhaps next year, when it will be possible to stream any programme, iPlayer-style, down a phone line to the television via an enhanced Freeview box. If that works - the idea is being worked on by the BBC, BT and ITV - then it is not so obvious that viewers will need YouTube to catch up with the next Susan Boyle.

ITV's problem is that it cannot wait that long; she is with us now.

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