there is no problem to generate a billion revenue that costs a billion and half. Barings bank in 1995, Enron in 2002, Merrill Lynch in 2008 ...
>in 2000 companies were IPO'ing without any significant revenue or traction.
Of course, nobody would fall for this old trick of 2000 - IPO without revenue. So the new trick of 2011 is huge revenue, profit negative. You see, at the scale of a billion it is clear whether it is a profitable scalable business model or not.