Pandora's Eyes Are Bigger Than Its Wallet

Pandora said late Thursday that its business is going gangbusters -- so wonderfully, in fact, that it needs to fire 7 percent of its main workforce in the U.S.

The good news is the online radio service is doing better financially than it told investors to expect. Revenue is higher than predicted, at least in part because the company is willing to cram in more commercial breaks between songs. And there's a good reason for Pandora's eagerness for higher advertising sales at the risk of annoying its users with ads: It needs the money.