There is a point in the life of any product when it has been beaten with the pointed stick of promotion for so long, and so ruthlessly, it no longer even twitches as the blows continue to rain down.
Such is the saturation of the market, every avenue for renewal, for re-sparking interest, has been pursued, and there is nowhere left to go.
It is at such times bright-eyed marketing geniuses step forward into the limelight, to shine like a neon sign left burning after midnight in a dead-end country town.
Take toothbrushes.
What most people knew as a plastic rod with a brush on the end used to polish teeth had a complete makeover, as a shocked public discovered to its horror the whole mouth, tongue and gums had to be brushed with a unique cheek and tongue cleaner: a piece of ridged rubber glued to the back of the brush.
That's after you turn on the battery-powered sonic vibration device.
The same phenomenon has hit the CSI-style brand of criminal justice television, so ubiquitous forensic television programming teams have calculated 97.3% of programming is now of this genre.
But the creative power-brokers that gave David Caruso a second shot at fame, and the opportunity to make removing his sunglasses and saying something lame a television moment that may define the new century, have hit back.
Two new American crime shows have each developed a crime-fighting technique, and a hook no viewer will be able to counter with a channel-changing device, that is infallible.
Lie to Me (TV3, Tuesdays at 8.30pm from tonight) stars Tim Roth as Dr Cal Lightman, a Washington-based deception expert who can see lies in the facial expressions, body language and intonation of everyone around him.
And his powers are little short of supernatural.
"He spent, like, three years in the African jungle with some primitive tribe studying their eyebrows," an impressed student of his methods reveals.
"The truth is written on all our faces," Dr Lightman says, before solving the murder of a school teacher.
With plenty of hand-held camera work, and the now essential scene of our protagonists sweeping down a hallway discussing their latest case, Lie to Me is a triumph of creative renewal.
Law and Order: Criminal Intent's trick is to cast Jeff Goldblum as the replacement for Chris Noth.
As Detective Zach Nichols, Goldblum steps straight from Jurassic Park and Independence Day, and any confusion is avoided by him playing exactly the same character he plays in those movies, exhibiting maximum quirk.
"Brilliant cop, very perceptive; both his parents were shrinks," a colleague says.
He does not appear to have any special skills, but so cleverly wraps up a murder in a warehouse full of young people, who play guitars and use young people's language, his crime-fighting skills are evidently without peer.
• Law and Order: Criminal Intent (TV3, Sundays, 9.30pm) is a triumph of creative renewal.
