The raising of the "platform society" and UGC 2.0 focusing on more and more practices happening in online social media environments brings about new opportunities but also new concerns for the increasing amount of information people share online. Personal information that people share online is becoming a contemporary treasure that feeds the phenomenon of "big data" commodification. The book offers a critical introduction to the logic of social media platforms by developing a clear and critical understanding aimed at improving the reader's "digital literacy".