The present stage in the evolution of the Internet, commonly called Web 2.0, has revolutionized the way people communicate, interact, and share information and has radically changed the way customers search for and buy products. The increasing adoption of Web 2.0 applications and technologies has led to an explosion of customer-generated content and has opened new opportunities for networking and collaboration among customers. Web 2.0 applications have brought about a new media category, the Social Media, increasingly growing in importance at the cost of traditional media. The Social Media have changed the power structures in the marketplace; evidence points to a major power-migration that is taking place and to the emergence of a new breed...