> if radio and Pandora are used significantly differently (which I don't strongly believe: as you say, it's played in cafes in place of radio). I have to disag

> if radio and Pandora are used significantly differently (which I don't strongly believe: as you say, it's played in cafes in place of radio). I have to disagree: I think the vast majority of people listening to Pandora are doing it on their laptop on headphones, while many radios (today) are not being listened to by a single listener. Regardless, the estimates I used intentionally underestimated the Arbitron radio audience numbers by an order of magnitude. Some of the larger markets go up to 150k listeners on the top station. If you're right and significantly more than 1.0 people listen to a particular Pandora stream on average, then it still have to be more than about 5-10 listeners per instance before it hits the numbers that radio is claiming. And I would be very, very surprised if the average were anywhere near that high. I think if Pandora had evidence of that, they would be able to demand more money from advertisers, for one thing. As to the methodology of Arbitron: Not really relevant for my purposes, because I think that it's accepted by advertisers as reasonable. At some point, if the numbers were complete garbage, the advertisers would have noticed and stopped relying on them; advertisers certainly track the results of their campaigns, after all.