Watching the democratic convention, as Luke (ben Tim) Russert is interviewing Will.i.Am of 'Yes We Can' fame.
Russert asks what Mr. i.AM thinks of the Republican attacks that Obama is a mere celebrity, given that he himself is a celebrity. And though I'm guessing some will dismiss it, he actually has a great response "Celebrity is not a bad word". When there's a disaster, it's celebrities that frequently raise awareness and money.
Trivial? Not at all. Rallying the masses towards some end isn't an easy task. We have beacons (signalers) for a reason. Raising money is one benefit, but there are several others. So anyway, good answer.
If you're interested in the econ. of celebrity, you should read Tyler Cowen's 'What Price Fame'.