Clients who don't use ratings are the likely advertisers of this oldies station. They are business that actually want to appeal to seniors and are looking for the few voices in local media who actually deliver seniors efficiently.
The station is probably the only commercial music station attracting a predominantly senior audience. Classical music and jazz might attract seniors, too, but not on AM, and besides, those genres are only played on noncommercial FMs.
Conservative talk and sports also do well on AM. Do any of Saul's clients also advertise on those stations or are the talk/sports outlets all doing agency business exclusively?