For me, the trouble with psychology stuff is that I find it too interesting — I just want more… but I need to focus my time on my business. Kevin’s stuff is among the worst because it’s among the best… I want to listen/read/learn more. I believe Kevin’s material is up there with the work of Stephen R. Covey, Robert B. Cialdini, and other masters. Fortunately, Kevin’s material is also about getting your finger out and doing. And it works.