The broadcasting world is a very temporary place. People skip from channel to channel. Presenters follow their pay packets from network to network. Yesterday's huge innovation is tomorrow's forgotten fad.
The BBC is not immune to this, with programmes and presenters behaving exactly as their commercial counterparts. But the mammoth, immovable presence of the BBC has acted as a drag on people's perceptions. Against an organisation practically unchanged since 1927, all others look temporary.
In modern eyes, satellite and cable channels are the other end of the spectrum. They appear with varying degrees of fanfare, then either blend in with the hundreds of other channels or crash and burn. Who now remembers Lifestyle, Screensport, the original, black-and-white programmed Bravo?
In the middle sits ITV. A curious blend of the temporary (short, fixed-term contracts) and the permanent (the longest serving company has been in situ since 1956). ITV programmes react ,as if somehow more volatile, with more speed than others - a popular show may find itself on air almost permanently, an unpopular one will disappear almost instantaneously - while other broadcasters plod on through public interest or because they have nothing to fill the space.
ITV is even more curious when you consider the nature of its temporary existence. While most channels live or die by the balance sheet (or in the case of the BBC, by the government and the middle classes), ITV until recently lived or died by the quango.
The Independent Television Authority was created in 1954 to supervise the new network. Under Sir Kenneth Clarke, the Authority decided the exact nature of the new system and appointed private contractors to run regional stations for a set period.
The sordid world of economics rarely came into it. Contractors were at the mercy of the markets and their bankers, but the ITA, while mindful of their financial stability, did not require money upfront to gain a contract. Instead, quality, or the promise of quality, was all that was required.
When Independent Local Radio appeared and the Authority swapped 'Broadcasting' for 'Television' in its title, they continued their short-term/long-term, finance important/unimportant policy in the new medium. This, almost inevitably let to criticism that the process for procuring or maintaining a hold on a contract was neither clear nor open.
In fact, the IBA were always open in their dealings, but the idea that radio and television should be treated as an art, with contracts going to the most promising artist slowly became alien to the people who set the socio-political agenda in Britain.
Thus the system was replaced by one entirely decided on by money, and soon the companies themselves had forgotten that it was ever different - or that it could be different.
Money is something understood by all. The idea that TVX paid more than TVY and therefore deserved a contract seems to make more sense at first glance than the notion that TVY may have been a better, if financially poorer, artist.
Perhaps that is the cruel irony - an artistic medium run by bankers; a money-making exercise producing art. On the see-saw of life, while one side is up, the other is down.