"D Peter Maus" wrote in message
...
David Eduardo wrote:
"Bart Bailey" wrote in message
...
In posted on Fri, 6
Jun 2008 23:42:49 -0700, David Eduardo wrote: Begin

The data is accurate... it is the Arbitron ratings.
Yep,
as accurate as whomever with free time to participate in the survey
faithfully keeps their diary.

You obviously don 't know that there are studies that show that
no-participants have essentially the same behabiour as participants?
If the diary methodology was so accurate, there would be no need to
encumber broadcasters with PPM.


The measurement is very accurate, but it takes three months per cycle to
measure and then 30 to 45 days to tabulate. The PPM delivers weekly results
10 days later. Advertisers want immediacy. The results of the PPM today are
less accurate than the diary, but they are faster.