Ten thousand music fans at a summer music festival on the waterfront is impressive, a nice feather in a radio station's cap. But it doesn't prove the station itself drew every fan to the event, nor does it prove the station has better ratings than what appears in Nielsen. Not that Nielsen or Arbitron is infallible. It's just that judging a radio station's success by the number of people who attend a rock festival on a sunny day in Buffalo is equally infallible. "Yeah, our ratings in the Spring book were a little soft, but ten thousand people came to a concert event we sponsored." There may be a few potential clients who will be swayed by that pitch, but only a few. Bars, maybe. Small concert venues, perhaps. Agencies? Nope. Local direct car dealers. Not likely. Show me the ratings, show me the cost per point or cost per thousand. Show me the average persons per quarter hour. Show me the cume. That's the way it works when the big money is on the line, whether it's transactional or relationship selling. That's the way Entercom sells Star, Kiss, WGR and WBEN.