I have only started to delve into what is archived in the Ephron On Media archive site. As Erwin Ephron says on his bio page “He writes things down.” He’s a media planner kind of guy who writes interesting stuff about the media. His latest cover story is titled “REACH TRUMPS FREQUENCY How Radio Can Build Business in A PPM World.”
You might want to check it out and get his perspective on media and how it can and should be used and evaluated. For an example, his latest article on radio starts out: Whenever I hear “Radio is a frequency medium” I shudder. It implies two things, neither good. Either Radio messages don’t communicate very well, so you need say it again and again just to be sure. Or Radio’s reach is so limited that any typical schedule soon runs out of new listeners. I won’t argue with that. You can register on his website and download the full article.