How self-disclosure builds cancer communities through authentic stories on YouTube: Mediating role of user participation in self-disclosure reciprocity

Self -disclosure is a communication strategy widely used to convey authentic personal experiences among video bloggers (vloggers) on YouTube. While self -disclosure plays a vital role in attracting viewers, whether selfdisclosure enables vlog communities to thrive is relatively unknown. While scholars have suggested that reciprocal self -disclosure between vloggers and viewers can generate basic community resources, few have examined the role of this reciprocity in the context of cancer vlog communities on YouTube. Furthermore, the two types of user interaction distinctive to cancer vlog communities (i.e., individual -level and community -level), as key drivers of community success and sustainability, call for investigation. To address these research gaps, we explored the mediating effect of user contribution on reciprocity of self -disclosure between vloggers and viewers in cancer vlogs on YouTube. Analyzing linguistic features and expressed sentiments in 503 cancer vlog videos and 194,300 associated comments, we found that self -disclosure among vloggers discouraged viewers to comment, in turn dampening reciprocal self -disclosure among viewers. However, the sheer number of comments by viewers encouraged self -disclosure among viewers. The findings suggest that reciprocity of self -disclosure from viewer to vlogger was less likely to occur at the individual level (i.e., vlogger to viewer) when other users ' comments were salient. However, contributions by other viewers cued community homophily at the community level, helping viewers leave their comfort zones to share personal stories with other viewers.