In the early 1980s, I did part-time political talk radio in Boston, as guided by the station pros.
Their metric for success then was the number of calls one got. One temporarily successful show was that of a psychic, who did her thing with the callers. Eventually, someone realized this was too low even for talk radio: lots of callers, not much value, perhaps few listeners.
My political talk show (on WMEX-AM, then WITS-AM) was a rarity, being from the right, although Avi Nelson and David Brudnoy and Dan Rea were also of that persuasion. The pay rate was middle-class, but one hoped to be making a difference.
What was hardest to do, and what Rush subsequently did so well, was talk without a guest and without callers, for long periods on his show, with ease, insight, humor, and courtesy. Furthermore, he later showed you could become rich from radio.
When Rush moved to New York and started his national show in 1988, I was among his first listeners, and I recognized his talent immediately, though I had no idea he would be so successful. He made what was hard look easy.
Rush re-wrote the book on being a talk-show host, and we find most of his fellow hosts now following his lead. He showed how to make the talk genre thrive. It took courage to be different, and he flourished.
I wish I could have known him personally.
He is missed already.