The challenge is that these companies are generally pre-revenue and potentially years away from profitability -- if that's in their future at all. Unknown factors such as timing, amount, price and terms of future rounds of financing make valuations something of a guessing game.
Silicon Valley / San Jose Business Journal - by Lindsay Riddell
Full Story: http://sanjose.bizjournals.com/sanjose/stories/2008/04/21/story11.html?b=1208750400^1622067