Facebook = $15B?

I've no expertise whatsoever in valuing companies, but...

I've seen repeated stories on the Net valuing Facebook at 15 billion dollars thanks to a naive running of numbers disclosed with the recent Microsoft deal--and every time I've seen the figure, I've found myself rolling my eyes and whispering "Shyeah..."

Former executive editor of Harvard Business Review Nicholas Carr writes:

The "$15 Billion" Nonsense.

So... all I want to say is...

Yeah, what he said.