In recent years, the use of Web-mediated digital technologies has constantly grown in importance, reshaping the communication landscape in all professional activities. Web 2.0 applications and platforms have evolved dramatically, exceeding all expectations, and have had an impact on all areas of activity, from personal and social to political and economic. A crucial role in this radical transformation has been played by social media, i.e. online resources enabling users to connect, interact, and share contents. They have changed social relations profoundly on an individual level, but also in their professional dimensions, transforming the dynamics of how professionals work, share knowledge and relate to each other and to their clients. This book explores online professional blogging and networking platforms, discussing methodological issues involved in analysing webmediated professional communication in a genre- and discourse- analytical perspective, with a focus on the structural and textual properties of genres on the Internet. The discursive objects investigated include professional weblogs, and in particular law blogs, professional groups on Facebook and LinkedIn, and LinkedIn job ads. Among the aspects examined are continuity with pre-existing traditional genres, generic integrity, and the debated status of social networking sites as platform users' communities of practice.