If you are a manager who doesn't focus on data and measurements - well, good luck. Being great is going to be next to impossible.
But what does focusing on data mean? This book is a great introduction to how to use data effectively. It teaches in the form of a story - a new manager who has to come in and make changes and uses data to get buy-in and support. Like most of these business stories, it makes it seem a little too easy. For example, the reluctant employee seems to fall into line and be supportive a little too easily.
Overall, the book does a good job of not just introducing concepts, but showing how they can be used effectively in the workplace. Some people might find it a little simplistic, but it really does the job of explaining what data is and how it can be used.