What Joe B the liar (WLS PSAs, self-promos) doesn't get about radio in general and Rush's large audience in particular is that any station in any market not airing Rush's show would kill to have him in their lineup.
In Chicago, for example, if Rush left WLS for WIND or any other station, his audience would follow him. It happens all the time in markets across the country. Syndicated radio hosts switch stations quite often for a variety of reasons. That's the broadcast industry.
All 40 Cumulus stations (6% of approx 600 stations) could drop Rush when their contracts expire if they wanted to, but the ad revenue from the replacements would be miniscule by comparison and they know it better than anyone else.
The point in the OP here (for point 1) is that that "any station would kill" factor is dwindling, and has been for a few years now. Maybe once they would "kill", more recently they would "maim"; today they might write a strongly worded letter. This is a trend; Blimpo is on his way out. That's why WABC and WLS can't sell enough ads; decreasing audience.
That was the whole point in Limpblob's character assassination a year ago: a desperation move to try to build up ratings and make himself 'relevant' as regards radio listenership. It kind of backfired according to Cumulus' figures of lost revenue since then.
Point 2, somewhat redundant, yes Lush's audience would follow him to WIND (the perfect set of call letters) but again the point is the audience that would follow is not that much any more. Plus it would be a demotion in signal area:
WLS contour, 50 kilowatts:
WIND contour, 5 kilowatts:
-- that's in the
daytime; at night WIND has to lower its power while WLS does not. This is the kind of demotion Lush has to deal with as a result of his fading relevance.
WLS is a "clear channel" station, one of a handful of stations authorized to broadcast at full 50kW power day and night; this kind of reach is the goal of a talk radio host. In Philadelphia the clear channel station that was carrying Limbo (WPHT which I can hear here in western Carolina and monitored clear as a bell from Cape Breton Island), dropped him after Fluke, and now he's relegated to an FM station in New Jersey-- off the AM dial altogether, and at an undesirable frequency to boot (106.9). That's called encroaching obscurity. That's the world of radio telling Rimjob "thanks for playing".
As for point 3, if all 40 Cumulus stations dropped Limblob, well their ad revenues after that is an unknown at this point, but as my David Frum link notes they're already laying groundwork with the Huckabee show-- Cumulus
owns that show. And they also own over five hundred radio stations, including WLS and WABC. So it's not like they're not prepared.