Major update, though the overall messaging is the same. It is a much more high-quality book. The first one was self-published and this one is published by Penguin Random House. So the first thing is it re-edited all the way through. We ended up cutting out about 50 pages, even though we added a couple of sections.

Second, the sections we added were a preface about my struggles with getting traction and a testing addendum giving 1-3 suggestions of how to test each of the nineteen channels (something people continually requested).

Third and finally, I really focused on rewriting the five introductory chapters to focus on things I saw readers of the first edition struggle with. We simplified the framework from 5 to 3 steps, and tried to shed light on the more non-intuitive aspects (like don't prematurely optimize marketing tests, etc.).