'This is a promising textbook for anyone eager to understand platforms as a business model and an economic concept. The book's systematic review of platform theories — in a wonderful mix of digestible algebra, intuitive explanation, and real world cases — is very much needed, especially when the public discussion about platforms is riddled with anecdotes and speculations. I cannot wait for the second book in this series, which will focus more on the concurrent policy debates about platforms. Both books have the potential to become a 'go-to' reference for platform economics, and to hopefully foster a deeper, healthier, and more comprehensive discussion about platform-related policies.' Ginger Zhe Jin, University of Maryland