First Break all the Rules is relevant to this discussion. It also has the virtue of being very data focused (they did thousands of surveys to come to their conc

First Break all the Rules is relevant to this discussion. It also has the virtue of being very data focused (they did thousands of surveys to come to their conclusions). here's a summary of the key conclusions. http://www.refresher.com/!breakalltherules.html http://www.refresher.com/!breakalltherules.html