This press release explains the method of valuation: http://37signals.com/svn/posts/1941-press-release-37signals-valuation-tops-100-billion-after-bold-vc-inves

This press release explains the method of valuation: http://37signals.com/svn/posts/1941-press-release-37signals-valuation-tops-100-billion-after-bold-vc-investment http://37signals.com/svn/posts/1941-press-release-37signals-... "When it comes to valuation, making money is a real obstacle. Our profitability has been a real drag on our valuation" :)