This special 10th anniversary edition of the bestselling The 80/20 principle contains an entirely new chapter 'The Yin and Yang of the Principle' in which Koch responds to the thousands of reader responses to the book - including a rap song! - and uses this new material to reach a new level of awareness and understanding of the true power of the principle.And it is powerful: the 80/20 principle - the fact that 80% of results flow from 20% of causes - is the one true principle of highly effective people and organisations. The 80/20 Principle shows how you can achieve much more with much less effort, time and resources, simply by concentrating on that all important 20%.The 80/20 Principle is the key to controlling our lives. If we can latch on to the few powerful forces within and around us, we can leverage our efforts to multiply effectiveness. Most of what we do has trivial results. A little of what we do really matters. So if we focus on the latter, we can control events instead of being controlled by them, and achieve several times the results.