This book aims to compile and thoroughly examine the motivations for using social media based on psychological and neuroscientific findings. Additionally, it will compare these motivations with those of traditional mass media to identify any differences. Furthermore, neuropsychological mechanisms that contribute to the intensification of certain behaviors will be presented and linked to social media. Based on the insights gained, hypotheses will be derived that offer a potential explanation for the intensive use and success of social media, especially in comparison to traditional media. To concretize the phenomenon of social media as the subject of this book, the first chapter will provide a comprehensive overview of this type of media and its success. The relevant aspects of motivation will be examined in detail in the following sections, initially from a psychological perspective and subsequently from a neuroscientific viewpoint. Special attention will be given to the reward system as the neural correlate of motivation. In the context of media psychology, the motivation related to media use, particularly social media, will be investigated more closely. The aim of this chapter is to compare the motives for using mass media and social media. Before concluding the book with a summary of the findings and the derivation of hypotheses to explain the success of social media, neuropsychological mechanisms stimulated by usage will be described. This will include the effects of social media use that lead to an intensification of usage based on the principle of positive feedback.