Customer Buying Hierarchy

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

Googling for "Customer Buying Hierarchy" shows no other references to this, other than this blog entry &#38; related videos. Can you provide some other pointers to where others might use this concept?