That's a good question: When radio people talk about "New York" or "Buffalo" or "Dallas" they really mean all the counties in the Metro Survey Area. And the data we refer to on population characteristics is for the MSA, not individual cities and towns in the market.
Very often, those who don't work in radio look at city data, so it's important to know that there is a difference in the way we look at things. Oh, and the government Metropolitan Statistical Areas are often different than radio MSAs... so one can find conflicting population data if the wrong "metro" definition is used. To make it even worse, TV "metros" are not generally the same as radio ones.