The main purpose of this book is to show companies, managers and marketers that social media creates a lot of new opportunities for them. Communities and networks are getting more important in this new Web 2.0 based world. The last decennia''s it cost a lot of effort for managers and companies to reach their target customers. The internet, and especially social media, gave these managers and companies'' new useable channels to reach their consumers again. Managers are now able to reach their target customers through micro marketing. This research showed that it is not only possible to reach the customers again, but also to predict the behavior of these consumers based on what kind of community they belong to. Within this research music preference based communities were used.