Social network sites (SNSs) not only strengthens an existing offline relationship, but also facilitates the formation of a new online relationship. As a result, there coexist the online ties between offline friends and online ties between two users who do not have any offline interactions and connection in SNSs. We investigate the nature of offline ties and its roles on tweet diffusion. We observe some interesting findings: (1) people can spread more efficiently (with fewer hops) their tweet on their offline friends’ local network; (2) offline ties play an essential intermediary role in facilitating pairwise tweet dissemination on each other’s local network; (3) As either in-degree centrality of a network or the number of community clusters increases, the information flow efficiency and edge-between centrality increase
