This is based on Steve Blank's experience as a serial entrepreneur: he graduated from the school of hard knocks and is not given to academic gobbledygook.

This presentation is condensed from his book "Four Steps to the Epiphany" which is well worth reading. Eric Ries has written a good post that marries this methodology with agile at http://startuplessonslearned.blogspot.com/2008/09/customer-d...