The behavior of Internet users: from websites to social networks.

Summary Over the past twenty years, the Internet has profoundly changed the marketing and communication professions. In this context, an in-depth understanding of Internet users' behaviors and their evolution in a constantly changing technological universe has become essential. My research is situated in this context, and focuses on the evolution and modeling of Internet users' behavior, from websites to social networks. This HDR report describes all my work and is divided into three parts. The first one presents my contributions to the study of Internet user behavior, which details work on the reconsideration of the explanatory factors of customer satisfaction, on the retribution of the Internet user in online studies and on the study of the reactions of the individual to digital identification processes. The second part deals with my contributions to the modeling of multi-agent behaviors on the Web during viral marketing campaigns, in which I detail the different types of modeling of viral marketing phenomena, the contribution of multi-agent systems and Petri nets, and finally the application of Petri nets to the modeling of emailing campaigns and viral interactive games. The third part focuses on my contributions to the understanding of Internet users' behaviors on social networks, with the aim of developing effective marketing strategies. In this part, I will focus on information dissemination processes on social networks and metrics, customer relationship management on social networks, and finally on new perspectives related to social networks in marketing.