A quite elaborate, though not rigorous, analysis of all the numbers that you should be looking at in every stage of an early startup. When I was building my startup, I found myself correcting the course I was on several times as I went through this, despite having an extensive background in lean beforehand.
Particularly useful is the analysis of the One Metric That Matters (OMTM). The clarity that this provides really helps with focusing and cutting out all the noise. The case studies that are included, while not all examples of lean, show how you can sprinkle this thinking into your startup without fully committing to it and still get fantastic results.
If I could go back in time, I would read The Startup Owner’s Manual: The Step-By-Step Guide for Building a Great Company first, and then read this once I got to phase 4.
I would have liked a primer on how to measure the success of marketing campaigns, but I suppose that I could find that in other books.