do radio stations have a listener counter that tells them how many people are listening? same question for TV?

Answer 1

listeners and viewers are chosen at random 3-4 times a year to keep "diaries" of the listening/viewing habits...these diaries are then tabulated by companies such as arbitron and neilsen to come up with the final numbers...

that's the easiset answer...cuz it do get complicated at times!...

Answer 2

Not sure. Mostly they're guessing or relying on Nielsen testing families for TV and Arbitron testing families for radio. Then some radio stations used to have employees working evening hours calling people randomly, asking what radio stations they like to listen to the most.

Answer 3

I doubt they can actually count.
Tv uses ratings where they ask a few thousand people (or record)what they watch and they guess from that what the rest of the people are likely watching kind of like election polls