37signals has a related post:

http://37signals.com/svn/posts/2283-ranking-tech-companies-b...

I have not checked their figures but in the case of these companies, the proposed 100K formula is mostly way off the mark.

As for NASDAQ-100 companies, the following chart is very informative:

http://www.jbryanscott.com/2009/02/07/nasdaq-100-revenue-per...