Spatial dissemination metrics for location-based social networks

The importance of spatial information in Online Social Networks is increasing at a fast pace. The number of users regularly accessing services from their phones is rising and, therefore, local information is becoming more and more important, for example in targeted marketing and personalized services. In particular, news, from gossips to security alerts, are daily spread across cities through social networks. Content produced by users is consumed by their friends or followers, whose locations can be known or inferred. The spatial location of users' social connections strongly affects the areas where such information will be disseminated. As a consequence, some users can deliver content to a certain geographic area more easily and efficiently than others, for example because they have a larger number of friends in that area. In this paper we present a set of metrics that quantitatively capture the effects of social links on the spreading of information in a given area. We discuss possible application scenarios and we present an initial critical evaluation by means of two datasets from Twitter and Foursquare by discussing a series of case studies.