What were the demographics of commercial talk radio in the '60s, '70s and '80s, before the Rush revolution, which signaled the decline of local/general-interest talk and the rise of angry ultra-conservative talk? I know that people like Bob Grant (WABC) were doing angry conservative talk in the '60s and '70s and always figured, even then, that most of their listeners must have been at least in their 50s.
So, were younger people actually listening to talk in the heyday of the 50kw AM talk blowtorches, or was advertising research not sophisticated enough for the agencies to tell clients that 55-plus wasn't worth the effort of trying to sell to?