This book is only intended as a short introduction to Gamification. There are plenty of other great resources out there which delve into much deeper detail. Two books I would personally recommend are Game of Work by Charles Coonradt, and The Multiplayer Classroom by Lee Sheldon.
Game of Work
In "Game of Work", Charles Coonradt relates his experiences in the industry for a number of large and small businesses. In particular, he encourages that scores be kept, that they are easily understandable, easily available, and that feedback is frequently given. In turn, this encourages the players to maximise their score, while teaching them the best way to do so.
The Multiplayer Classroom
The Multiplayer Classroom is much more focused on applying Gamification to education, however still has much to say about the subject in general. Lee Sheldon relates his experiences as a Professor and Game Designer, applying ideas such as experience points and quests to coursework and learning. Even the book itself is gamified, with levels instead of chapters!