I heard about the concept from Clayton Christensen's Innovator's Dilemma. http://www.amazon.com/Innovators-Dilemma-Revolutionary-Business-Essentials/dp/00605219

I heard about the concept from Clayton Christensen's Innovator's Dilemma. http://www.amazon.com/Innovators-Dilemma-Revolutionary-Business-Essentials/dp/0060521996 http://www.amazon.com/Innovators-Dilemma-Revolutionary-Busin... The book talks about the buying hierarchy in the context of disruptive innovations. It's highly recommended.