Broadcast Versus Viral Spreading: The Structure of Diffusion Cascades and Selective Sharing on Social Media

Sharing cross-ideological messages on social media exposes people to political diversity and generates other benefits for society. This study argues that the diffusion patterns of political messages can influence the degree of selective sharing. Using a large-scale diffusion dataset from Twitter, this study found that messages that spread through multiple steps are more likely to involve cross-ideological sharing. Furthermore, the study found that this positive relationship is mediated by the distance between the sharers and originators of the messages and suppressed by the number of connections among the sharers. Overall, the study found that the viral diffusion model, in contrast to the broadcast model, increases the likelihood of cross-ideological sharing and thus increases political diversity on social media.