The short answer is: 'they do'. As for the long answer...
TV ratings - why all the fuss
A new system was introduced in January 2002 to measure the audiences for UK television. But initial 'teething problems' became a fully-fledged crisis - leaving both TV companies and advertisers unsure as to who is actually watching what. In fact, the problems have only just been resolved.
You've obviously never watched a group of media types getting drunk at lunch in a Soho brasserie, have you
The ratings are all-important in Medialand. The larger an audience that commercial TV can offer to advertisers, the more than can charge for adverts. And with a general downturn in advertising spending anyway, it's crucial that the figures are accurate (and that they look good).
And what went wrong
TV audiences are measured by an independent company called BARB (British Audience Research Board), jointly owned by the major TV networks and the Institute of Practitioners in Advertising.
BARB operates a panel of TV-viewing members of the public selected to represent the viewing habits of the nation as a whole. At the start of the year a completely new panel of households was introduced. They've removed demographic disproportionality and improved geographic representation, you'll be glad to hear. And... it all started to go wrong.
There are more households on the panel, up from 4,300 homes to 5,100. Or there should have been. But BARB had trouble getting everyone to operate the new technology. Other changes are designed to make the ratings even more accurate representative.
... but what the new ratings actually did was show that less people are watching TV than had previously been thought. Adland and the TV companies went ballistic. ITV1, for example, 'lost' some 25% of its audience when the new system was first used. BARB countered that the figures are more realistic... while also admitting 'unforeseeable circumstances' causing problems with the new panel and the new technology.
Considering how few people can set a VCR, it should come as no surprise that people are having problems coming to grasps with their new metering equipment, known as the 'peoplemeter'.
Sadly for all concerned, the people having the most problems appear to be 16 to 34-year-olds and high-earning ABC1s.Or in other words, the very people that advertisers really want to reach.
Has anyone done well out of the new ratings
The full panel is now up and running (five months behind schedule) and viewing figures for multi-channel TV are up. Great news for the likes of Sky, terrible news for the likes of ITV, who have the ITV Digital fiasco hanging over their heads as well.
Meanwhile, with the licence fee safely banked, the BBC looks on, smiling (even though they profess as much concern about all matters BARB as their commercial counterparts: 'The figures just don't smell right to me,' opined BBC1 Controller Lorraine Heggessey).
Leaving the great imponderable of TV ratings
Who actually watches Crossroads We may never know her name for certain...