Facebook profits plunge by 80%
It may have more than one billion users, but Facebook announced a plunge in its profits of around 80% to $64m (£40.4m) in its second earnings update on Wednesday night.
Advertising revenue is now worth about $1.6bn (£1bn), and much more of it is coming from mobile users - but the amount Facebook is having to invest to get that advertising has Wall Street worried.
Michelle Fleury reports from New York.
31 Jan 2013