"Many of the principles of management that we teach are not universally true. We teach that you should always listen and respond to the needs of your best customers. We teach that you should focus your investments on the opportunities that offer the most attractive profit margins. It turns out that sometimes, in certain circumstances, these are the right principles to follow. When faced with disruption, however, these are the wrong principles to follow." -Clay Christensen Professor, Harvard Business School Thought Leader Forum 2007