Why are some ideas, processes and products (or, memes) popular, and others not? And - What is the unit of culture? For that matter: What is `Culture'? This short book synthesizes the Systems Model of Creativity (Csikszentmihalyi 1988, 2014) and Evolutionary Epistemology (Campbell 1974) to explain why some things are popular, and defines and describes the structure of the Meme, the unit of culture (Dawkins 1976).