In times of constant technological developments it is crucial for commercial organizations to remain competitive in view of the growing variety of online tools for doing business. These tools include advanced marketing techniques. This thesis analyzes the existiting legal framework in the EU, Switzerland, and the US with an attempt to suggest a balanced regulation of online service providers' and advertisers' activities in the context of social media advertising, having in mind the need to protect Internet users' privacy and personality rights. Particularly, this thesis addresses the legal concerns around the validity of consumers' consent to the processing of their personal data and the cross-border transfers thereof, as well as the appropriate legal regime for social media endorsements. Autorin: Frau Dr. iur. Mané Sargsyan