When people speak of having, say 5 million listeners of their radio show, how do they know? I know tv has those ratings boxes, but what does radio use? Do they have a segment of people that have similar devices to the ratings boxes tv uses? And then assume that for x amount of boxes that are listening to station **** y people are actually listening?
If this is the case would the method be flawed since due to the fact of them having such a device (if it were voluntary) they would be more inclined to listen to radio more?
If it isnt how it is measured how is it measured?
Also if anyone could explain how it actually works for tv feel free to explain that too.
