If you are a consulting geek, or like to read business history, The Lords of Strategy (affiliate link) is a fascinating and easy read. Helps you understand the economic, regulatory, and business trends that gave rise to the Big 3 consulting firms (McKinsey, BCG, Bain). Also, great trivia story about how the BCG “blue team” became Bain & Company. In the mid 1960s, Bruce Henderson, founder of the Boston Consulting Group (BCG), was reading a lot of books on paleoanthropology (caveman competition stuff), and decided to run an experiment on his own company. He divided the company into three teams (red, blue, and green mini-firms) and had them compete with each other. It worked (a little too) well. The blue team did the best. This team was led by Bill Bain and Patrick Graham, who would 3 years later leave BCG and form a new company, the eponymous Bain and Company.