"The Happiness Advantage" by Shawn Achor is a book that explores the connection between happiness and success in the workplace. Achor presents seven principles of positive psychology that can be applied to fuel success and improve performance at work. The book emphasizes the idea that happiness is not a result of success, but rather a precursor to it. Achor provides practical strategies and techniques to cultivate a positive mindset, increase productivity, and create a more fulfilling work environment.