Channel 4's decision to turn its pay film channel FilmFour into a free-to-air channel, funded only by advertising revenue, is a particularly interesting move and has ramifications for a range of different players in the broadcasting industry.
Nearly 400,000 subscribers have been paying £7 a month to receive FilmFour for some years now, but that clearly hasn't been enough to make a return for Channel 4. Chief executive Andy Duncan obviously believes he has more chance of getting the channel to turn a profit by making it available for free on all digital platforms - and accessible to something close to 20 million Freeview viewers - and selling adverts in the movies.
The first thing this is bound to mean is that the output of FilmFour will change. It will inevitably become more populist - just as the rest of Channel 4's output has become more populist in recent years - with many more commercial movies on offer.
However, the move also means that Channel 4 is now completely out of the pay television business, in common with the other two British commercial terrestrial players, ITV and Five. This is an odd position for British television to find itself in and it certainly bucks the international trend: only last month figures were published to show that, for the first time ever, in 2005 total pay TV revenues in Europe were higher than total advertising revenues.
Almost every large commercial media company in the world that has a stake in free-to-air television also has a stake in pay TV. Even those that haven't, like ProSieben in Germany (and here I have to declare an interest as I am a member of the company's supervisory board), are moving in that direction. So why are the British different?
Five has never been in the pay business, and ITV gave up on pay television in despair back in 2002 when ITV Digital went bust and has shown no sign of going back on that decision since. This left Channel 4 as the only terrestrial commercial player in the UK in the pay business, but that was before Duncan became chief executive.
Duncan, who came from the BBC where he was director of marketing, was clearly enamoured of free-to-air television. As one of the three or four people at the BBC most responsible for the creation and launch of Freeview, he watched its incredible growth and clearly decided that that was where Channel 4's future lay.
First he moved E4 out of the pay arena to make it free-to-air, and now FilmFour is following. So Britain is now left in the distinctly strange position whereby the only large terrestrial player also in the pay business is the BBC, which owns half of UKTV and is now making good money from it. And, of course, the BBC doesn't take advertising.
At a time when television advertising revenues in Britain are growing only very slowly but pay revenues are expanding faster, this is all difficult to fathom. On the one hand, Duncan is saying that Channel 4 can't rely on growing advertising revenue for ever and should have some public funding, but on the other he is walking away from the fastest growing revenue stream in British television - pay TV. He's clearly decided that, given Channel 4's current success, it can grab a bigger share of the advertising cake.
Of course the losers, as a result of Channel 4's decision, are Sky and the cable companies. Suddenly their basic pay propositions look less attractive while their biggest rival, Freeview, looks more sexy. Why take Sky and the cable companies' basic services, which you have to pay for, when you can have Freeview for nothing?
But it doesn't end there. What has really boosted Freeview is that Channel 4 will be heavily promoting E4 and FilmFour on its main channel, encouraging people to take Freeview. When you add to this the BBC promotions for their free-to-air channels on Freeview and ITV1's promotions for ITVs 2,3,and 4 - also all available on Freeview - suddenly things look very rosy for free-to-air digital television. And Five will be next with its new free-to-air channel.
But there is one caveat to all this. Is there enough advertising revenue to pay for all these channels? Because there's no sign at the moment of the total advertising cake expanding.
Causing a breach of the peace? You're nicked, son
For those who haven't seen it, the BBC's Monday night drama Life on Mars is well worth watching, not only for what it tells you about how policing has changed over 30 years but also how cop shows on television have changed.
The show is based around the unlikely premise of a modern-day detective being transported back in time to find himself working in the Seventies, an era when fitting people up was the norm, when suspects were regularly beaten up in police stations, and when explaining people's rights was seen as "namby pamby". In other words, he's back in the world of The Sweeney.
Thames Television's The Sweeney, closely followed by LWT's The Professionals, were probably the two most violent drama series ever made for British television. They were both around in the Seventies, both got huge ratings and both were constantly under attack for their aggressive content.
Some years later, when such violence was no longer acceptable, I remember wanting to show a repeat of The Professionals on LWT. I suggested that we "trim" the violence, only to discover that we ended up with a half-hour show.
The Sweeney in particular had unintended consequences: all sorts of ordinary policemen began to think they were Carter and Regan, the show's main characters. I knew one bloke who joined the flying squad, as it was called then, and when he was invited by another friend to pop in for a cup of tea if he was in her neighbourhood, replied: "We're The Sweeney, love. We don't pop in for tea, we kick the door down".