ya Boston may be a MSA for census and radio purposes but as far ad radio advertising it is broken down into much smaller areas unless you are a major client with multiple locations or have the ability to draw from distant places.
There are two kinds of MSA. The Census has a Metropolitan Statistical Area while Nielsen has a Metro Survey Area. As often as not, they are different. The Feds define their MSA based on commerce, while Nielsen does its definition based on "majority of radio listening to 'home to market' stations".
In some markets, like Houston, the radio metro can change by a county or two every year!
A Bernie & Phyl's, Jordan's Furniture, Bob's Furniture, and even a Cardi's might do well buying for the whole market, but to get from say Pelham NH in Hillsborough County NH, which is right on the MA NH line, lots of former Massholes living there and commuting to Boston, and going to say Plymouth MA, is on a good day a minimum 90 minute drive... In the summer, after 9 AM on a weekend, double that.
And that is what suburban limited coverage stations live on, just as suburban newspapers used to. Small businesses can't afford paying a full coverage station for areas they can't possibly get business from. But those suburban station get infinitely lower rates.
People from the "North Shore" and Merrimack Valley don't venture to the "South Shore" When a small restaurant, store, single location car dealer buys an ad on a full market coverage area station, the sales folks are going to have to have some pretty specific numbers from the rating service as far as the surrounding areas because a restaurant in Marshfield isn't going to get customer 1 from Andover and visa versa.
Most stations won't even approach restaurants. They are usually cash in advance or trade as that is the one category that has the highest bad debt percentage. And most restaurants put their money in online search-connected services, not radio.
Car dealers know they have to offer some advantage to bring people from the other side of town. Some do it successfully.
"Metro West"... someone from Upton Ma in Worcester County ( east of Worcester) is again, more than an hour on a good day from Plymouth MA.
Which is why the top stations pick up the national, regional and local agency business for bigger accounts. I managed sales for nearly a decade for a dominant #1 station in a Top 15 market and we did over 95% agency business. Nobody else could afford us.
The North and South Shores, Metro West, Merrimack Valley... they might as well be planets because they are pretty self contained and there is not a lot of movement from one to another for shopping purposes..... but those people will drive to NH for menthol cigarettes ( illegal in MA !) cheap beer, liquor, sales tax free major purchases they can bring home in the back of their friends pick up truck, fireworks, and a few other things. Oh ya no bottle deposit in NH either. There is a reason smoke shops and the NH State liquor store, and in season the fireworks stores advertise on Boston stations.
You are forgetting that a lot of advertising may be for non-retail categories, such as insurance, investments,. websites and many others.
But if anyone thinks for a moment that when Jeff Kuhner is plugging a dentist in North Andover, or a restaurant in Manchester NH that people from more than a 25 minute drive are going there, they are nuts.
And the dentist is paying $15 a spot while the leading news-talk and sports stations are in the $300 and over range, depending on the daypart. As I said, the restaurant is likely trade or has paid in advance.
