XTalker said:Finally, Arbitron wants us believe it is a zero sum game - that if one station loses a listener, another has picked one up. They call them trends. Truth is, sampling change alone can result in a ratings shift. The only way I believe they could track a true trend is to survey the same people over and over again for the whole year!
You might want to rethink that. It is a zero sum gang.
Shares are always 100% of radio listening. The pie is ALWAYS 100%.
If there are 100,000 people listening to radio and 10,000 people listen to a station then its a 10% share.
If the next book 110,000 people are listening to radio and 10,000 people listen to a station they only have a 9.1 share.
It is a zero sum gain as share is 100% people listening to radio.
Rating points are percentage of the population listening to radio (not just radio listeners as shares are) and it is not a zero sum gain - but then again, as most do not understand the difference and never see Ratings Points in any trades (its a very small number for most stations), most have no concept of what they are or how they work.