A five-year Standish Group study estimates that open source software is pulling $60 billion — about 6 percent — from the bottom line of proprietary software firms.

Studies of this nature are often flawed because they assume that those using software A would have purchased software Z. No details of methodology in the press release, which seems designed to generate scary headlines. (tip via Twitter)

A reminder: open source software itself generates revenue. An IDC study estimates that “$21 billion in revenues came from the Linux ecosystem in 2007 alone.”

Without a doubt, the open source model is disruptive to established organizations. However, disruptive does not necessarily mean “bad” for society as a whole.