In this book, we research the importance of marketing orientation in businesses and especially in the telecommunication industry. How a successful marketing orientation could contribute to better performance and productivity, how a business could differentiate its services from its rival's, how to achieve long lasting customer relationships and further contribute to the welfare of the modern societies. We research especially the Greek telecommunication market, its transition from state monopoly to privatization and the role of the Hellenic telecommunication and post commission (E.E.T.T). The research method used and the results are quite surprising as reveal the extent of the adoption of marketing orientation in the Greek telecommunication industry compared with the leading company which has the highest market share.