The main problem with radio is not the relatively small size of the playlists (although that doesn’t help); it’s that music is polarizing–people may like one song but hate the next, so they’re prone to switch stations or switch off entirely. As MTV found out a decade ago, there simply is no single playlist that can keep enough people listening long enough to please the advertisers. MTV switched to reality shows because they’re sticky. Radio is switching to talk for the same reason.

It is the curse of broadcast: with just a few dozen stations in each city, most must aggregate audiences in the tens of thousands. In an era of infinite choice and narrowcasting, such mass-market broadcast distribution–the ultimate one-size-fits-all model–just can’t compete.

— Chris Anderson on the future of music on radio

I have not heard the Jack format and think it unlikely I will. The little nano is getting more and more of my limited listening time (mostly podcasts, some music). I’m even listening to XM less since getting the little iPod.