This book is a must-read for a Product Manager and I consider it as my personal bible for Product. In a world where the PM role is so loosely defined and varies greatly between companies and teams, Marty's focus on creating value for customers in a way that works for the business is spot on.
Following the wisdom in this book has helped me become a better product leader, focus on what matters at my work, grow my product and team and even land job multiple offers from companies big and small. I go back to this book often and got a copy of it for my CEO & COO. Don't expect this book to solve your problems, but to help you lay the land and focus on the important things.