Metallica - Remember that they lost an entire fan base after they released their first single. Many fans believed they had sold out. These are the true fans. The ones who went to gigs and didn't care about whether the band released records or won worldide acclaim.
But doesn't this restrict Metallica somewhat? They release a single and suddenly they've "sold out"? What, your band has to make under a certain amount of money to be considered "real"?
And they, in fact, did
care whether the band released records or got famous. They cared that they didn't. The moment they did, these people up and ditched them because "you sold out man!"
Maybe they just expanded their fanbase?
(note: Metallica did sell out, but not as fast as their first single)