This burden falls mainly on media, as even the perfect focus group cannot count inspiration.
But in the space between the "trust me" of the creatives and the return on investment of dependable media, lives an inadequate occupant - media research.
Through this pretender, we affect the introduction of science to a creative process, entrusting the transaction of billions into carefully calibrated measurement systems - which cannot cope.
We know this.
We know media research fights a constant battle to define and to identify actual exposure to ads.
We know it is exceptionally hard to recruit certain types of (active, interesting, highly targetable) people to log their media consumption. And even if they do get signed up, there is a gruesome contrast between their hazy attempts to cobble together some replica of their media behaviour and the meticulous scrutiny this confection receives in our hands.
We know all this, but we don't behave as if we do.
We treat research information as sacrosanct. It drives media transactions without qualm or question from its users.
When a radio breakfast show apparently loses 250,000 listeners in one survey and gains 330,000 the next, media planners' decisions adapt as if this is really happening.
In press, where we have circulation data as the steady counterpart to bumpy National Readership Survey numbers, does anyone weigh readership numbers once they are delivered to our desks?
Defenders will argue that the media research we use is the best we can have for the money, and they have a point.
But this condemns us media people to bogus science, experts on these flaky information flows, and incapable of gaining a hearing for ingenious ideas that have not been cleansed in this sheep-dip of respectability.
Return on investment sounds like a great motto, and we can't blame media agencies for claiming it as their driving vision if this is what the clients want to hear.
But it is so much snake oil without the bravery to ascribe a higher respect to understanding than to data.
Media research is our servant, not our master.
- Richard Eyre is a media pluralist richard.eyre@haymarket.com.