Nowadays the market is becoming increasingly competitive. Consumers have a wide variety of choices and make their decisions based on the recommendations of other peers, which they consider more trustable compared to traditional advertisements. In such a scenario customer engagement is becoming the most important challenge for businesses. In fact engaged customers are not only loyal, but also active recommenders of the product/service to other peers. Social media, thanks to their interactive features, allow building relationships with customers and therefore they have a key role for customer engagement.   The paper analyzes how companies can use social media in order to build a customer engagement strategy. The project begins with an overview of the literature available about two main topics: customer engagement and social media.  In the later analysis, the author demystifies social media for business by analyzing what are the main functionalities that they provide and how these functionalities can be used in order to create a social media engagement strategy. A new model is presented: “The Social Media Engagement Cycle” that highlights how engagement on social media helps driving repeat sales and getting new customers through the existing ones. The author addresses the organizational and cultural implications of the model to highlight which are the changes that companies should address in order to implement a successful social media strategy. Finally the author discusses a case study from the telecommunication industry, and drives general conclusions about how the engagement on social media has a pervasive importance across industries.