Looking back at the first few posts of this thread, unless you listen to a "specialist" station, radio's playlists are dull, safe and entirely predictable. Radio 2 (Europe's most popular station) being the biggest culprit.
Every time Paloma fucking Faith has a new single out, I know I'm going to be subjected to it, 5 or 6 times a day, for at least a month. Rinse and repeat for Barlow/Williams etc.
Stations like GHR play "safe" music, as they don't want you changing channels, so THEIR advertisers lose exposure. They want you to hear
Chain Reaction
Brown Eyed Girl
Don't you want me baby
Tainted Love
Rio
True
etc. All stuff that EVERYONE knows, so people don't channel hop.
There's a programme on Absolute 80's on a Sunday, called Forgotten 80's, and yes, the DJ will play a song you've bot heard for AGES, then, two songs later, I'll be shouting at the radio "how the fuck is this forgotten?" They don't want you wandering. People like familiarity.