Impact of offline events on online link creation: a case study on events advertised on Facebook

Link creation in online social networks (OSNs) is one of the key-points to understand network growth. Studies are mainly devoted to discover the mechanisms built on features intrinsic to the network, but the role played by users' offline meetings on their online friendship creation has been often argued, but it has not yet been studied. Offline events are often advertised on online social networks, bridging the offline to the online users' social activity. We leverage this connection between offline and online sociality to build a novel dataset of events advertised on Facebook which enables us to take a first step towards understanding the effect of offline events on online link creation. In particular, we aim at answering the following questions: How participating to an event advertised in Facebook can change the structure of the online social network? How do friendships among attending people increase during the event?