Book excerpt: The definitive reference on free vs. paid business models. Marketing has been practiced for centuries around one central tenet: creating an effective message to potential customers so as to generate sales and profits. This method, while proven, is flawed by incompleteness: the message carries no value; only what is sold does. In recent decades, marketers added value to advertising and created so-called "free products". The Mind Share Market uncovers this hidden customer segment that can make or break a business. Through the story of Maria Ezrati, CEO of Etymologic Corporation and over 15 real world examples, executives and managers in all industries will find a philosophical and practical blueprint to understand the dynamics of a zero price.