Casual fans don't know the difference between the WBC, W-BNP, W-IRA or W-PONY title. As long as it's a shiny belt called world they'll buy it.

Bods that get to Froch's position - fame outside the boxing world, massive fanbase, PPV fighter, worldwide recognition etc, won't lose his audience because of a belt.

Belts are clearly important for younger fighters and "no fans" fighters though.