Everyone seems to think that Eric Reis was the first person to suggest the process of rapid iteration to find product fit. Jeffry Timmons was lecturing business students about a dynamic process of trial and error to find product fit 20 years ago.http://www.slideshare.net/akashpai/the-timmons-model-of-the-entrepreneurial-process
http://www.businessweek.com/smallbiz/content/apr2008/sb20080423_402595.htm