Re: What sustains a bands popularity
Well, if you look at what each 'major' band throughout the last few decades had in common with the next, I think it would be distinction.
Having your own style and your own sound is integral in becoming bit-time, because people like colorful music. If every popular band started to blend into the others, it wouldn't be as fun, or exciting.
Even within genres, bands are far enough from each other in sound to be distinctive. Try saying Korn and Slipknot sound exactly the same to a fan of both.
Oh, and playing gigs helps. Lots and lots o' gigs.
-Insert witty comment here-