First of all, you're likely making the mistake (again) of assuming that 6+ ratings are some kind of a success or failure scoreboard. Unless you see ratings in the target demographic and know the revenue therein, likely you're making assumptions not based on any reality. We've had this same discussion many times...
Something to consider, are listeners typically move back and forth between stations for many reasons. And now with streaming and apps, listening moves between radio to streaming, and back, but don't stay in one or the other forever. There could be a million or more reasons why certain listeners would move from one station to another. Common ones are: Age. As listener's get older, they seek out music from their youth. Commute: Strong morning personalities get the commuting audience more than a station just playing music. Ad rates for popular morning shows generally bring in much more revenue than just playing music in the same time. Promotion: Newcomers need to promote outside their own station to drive sampling. Change the wrong way:
Stations can lose audience by going in the wrong direction. Problem is; you don't always know what the reaction will be. That's why smart programmers don't make wild-swing changes without at least research to give some assurances you aren't going to kill yourself. Even then, patience is warranted. Make a change, watch the target, adjust slightly as needed. Don't panic if there is a dip. Watch the trend over several books.