title: Diffusion of Messages from an Electronic Cigarette Brand to Potential Users through Twitter.
abstract: OBJECTIVE
  This study explores the presence and actions of an electronic cigarette (e-cigarette) brand, Blu, on Twitter to observe how marketing messages are sent and diffused through the retweet (i.e., message forwarding) functionality. Retweet networks enable messages to reach additional Twitter users beyond the sender's local network. We follow messages from their origin through multiple retweets to identify which messages have more reach, and the different users who are exposed.
  
  
  METHODS
  We collected three months of publicly available data from Twitter. A combination of techniques in social network analysis and content analysis were applied to determine the various networks of users who are exposed to e-cigarette messages and how the retweet network can affect which messages spread.
  
  
  RESULTS
  The Blu retweet network expanded during the study period. Analysis of user profiles combined with network cluster analysis showed that messages of certain topics were only circulated within a community of e-cigarette supporters, while other topics spread further, reaching more general Twitter users who may not support or use e-cigarettes.
  
  
  CONCLUSIONS
  Retweet networks can serve as proxy filters for marketing messages, as Twitter users decide which messages they will continue to diffuse among their followers. As certain e-cigarette messages extend beyond their point of origin, the audience being exposed expands beyond the e-cigarette community. Potential implications for health education campaigns include utilizing Twitter and targeting important gatekeepers or hubs that would maximize message diffusion.
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Kar-Hai
authors.initials: KH
authors.lastname: Chu
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Unger
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Jon-Patrick
authors.initials: JP
authors.lastname: Allem
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Monica
authors.initials: M
authors.lastname: Pattarroyo
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Soto
authors.affiliation: Department of Preventive Medicine, University of Southern California, Los Angeles, California, United States of America.
authors.forename: Tess Boley
authors.initials: TB
authors.lastname: Cruz
authors.affiliation: College of Computing and Informatics, Drexel University, Philadelphia, Pennsylvania, United States of America.
authors.forename: Haodong
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Computing and Informatics, Drexel University, Philadelphia, Pennsylvania, United States of America.
authors.forename: Ling
authors.initials: L
authors.lastname: Jiang
authors.affiliation: College of Computing and Informatics, Drexel University, Philadelphia, Pennsylvania, United States of America.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Yang
mesh_terms: D000329:Advertising; D066300:Electronic Nicotine Delivery Systems; D006801:Humans; D033181:Information Dissemination; D007255:Information Services; D061108:Social Media; D060756:Social Networking