PirateJohnny said:
If you don't think listeners can revolt, study the 60s Pirate Radio phenomenon around Western Europe. BBC stations in England now play popular music, not at all like the 60s BBC programming.
Only two nations were affected for any period of time by pirates in the 60's: England and Holland. England spawned Caroline and a variety of lesser pirates, and Holland's Veronica was quite successful. Elsewhere, there was little pirate activity.
Much of England had had exposure to commercial pop radio for many years prior to the pirates in the form of Radio Luxembourg on 1439: they generated huge ratings in in the places they could be heard, mostly at night. And France had both Radio Monte Carlo 1466 and the two Andorra stations, although the influence was stronger in Southern France.
It can be said that the British pirates reacted as much to Luxembourg's success despite a lack of a solid signal over London in the daytime as to what the Bebe did or did not do.
There was no more a listener revolt anywhere in Europe than there was in Omaha in '52 when Storz put Top 40 on KOWH and decimated KFAB and WOW.
As for the rest of Western Europe... there was no revolt, either. Spain, for example, had a national network of commercial Top 40 FMs in 1966, long before the format had any independent presence on FM in the US.