Authors- Based on joint work with Jean Pouget-Abadie, Stuart Shieber, Oren Tsur, and Sam Wiseman

Abstract- In online social networks such as Facebook or Twitter users can advertise products and services by using appropriate labels to convey the content they publish is sponsored.  A growing concern is that many users intentionally conceal the commercial intent behind the promotions they publish, disguising them as authentic recommendations.

In this talk we will discuss the problem of covert ads in social media.  We will present a systematic approach for covert ad detection in social media platforms and use this approach to analyze covert ads. The main challenge is due to the fact that covert ads are not labeled and it is a priori difficult to distinguish their content from authentic recommendations.  We develop specialized algorithms for characterizing redirection links used for sponsored referrals, as well as classifiers for detecting content that is of commercial nature.  We then apply these algorithms to detect covert ads and study this phenomenon.  To evaluate the performance of the algorithms we use the Mechanical Turk platform which allows us to evaluate our algorithms using human annotators.