Open Access

Florian Probst

• Traditionally, researchers and practitioners engaged in the field of Customer Relationship Management (CRM) perceived customer relationships only as bidirectional connections between companies and customers. Thereby, companies were able to control the conversations to a large extent. However, the increasing digital connectedness changed the behavior of customers dramatically. Especially with the rise of Online Social Networks (OSN), such as Facebook, customers nowadays vividly exchange their experiences and opinions with previously unknown intensity, reach, and speed among each other. To account for these changes, users of OSN should be perceived as important communication partners who provide valuable feedback on brands, products, and services along the whole value chain of companies. The main objective of this dissertation is to contribute to the field of CRM with a particular focus on OSN and the identification of influential users within these networks. Therefore, the first partTraditionally, researchers and practitioners engaged in the field of Customer Relationship Management (CRM) perceived customer relationships only as bidirectional connections between companies and customers. Thereby, companies were able to control the conversations to a large extent. However, the increasing digital connectedness changed the behavior of customers dramatically. Especially with the rise of Online Social Networks (OSN), such as Facebook, customers nowadays vividly exchange their experiences and opinions with previously unknown intensity, reach, and speed among each other. To account for these changes, users of OSN should be perceived as important communication partners who provide valuable feedback on brands, products, and services along the whole value chain of companies. The main objective of this dissertation is to contribute to the field of CRM with a particular focus on OSN and the identification of influential users within these networks. Therefore, the first part of the dissertation defines the concept of OSN and reviews their development over time. Moreover, the impact and value of OSN along the value chain as well as major risks and challenges from a business perspective are outlined. The second part of the dissertation focuses on influential users in OSN. First, fundamental research on social influence, influential people, and their identification in social networks before the rise of OSN is presented. Second, the growing number of publications on the identification of influential users in OSN is analyzed and synthesized. Then, a research agenda is derived based on identified research gaps. Third, a novel PageRank based approach for the identification of influential users in OSN is developed, bringing together main findings from prior research. The novel approach is evaluated against existing approaches by means of real-world data. Fourth, another approach for predicting users' communication activity in OSN is suggested to improve the effectiveness of advertising strategies by addressing the most active users deliberately. Finally, the key findings are summarized and starting points for future research are highlighted.…