Actually I was interested how to write better user stories and people suggested to use this one - after I've already bought a copy though. ;) It started with lots of basics about the whole mapping stories and provided plenty of insights why and how to do. Later on, a more thorough walk through the whole MVP idea and how to really do it, which really helped me to get different view on the whole thing. So if you really want dive deeper into the story mapping, want to know why a story is called a story and how all those maps and mappings work - grab your own copy.