This ebook is laid out impeccably. It's very easy to follow, to skim, to jump around. Beyond that, it's also easy on the eyes; we love the overall design choices. Content-wise, Grin's use of case studies works great for driving home the point and adding reliable supporting evidence. The data scattered throughout works to the same end.
The organization of ideas here could use just a little bit of tweaking. We'd also love to see more clearly actionable advice. This is really a question of presentation. All of the metrics and "what you can do"s are useful and usable, but presented more like facts than actual how-to you can work with.