Multi-Platform Social Media Use and Incidental Exposure: A Two-Step Analysis of the Conjoint and Distinct Roles of Network Heterogeneity and Homogeneity Across Platforms

Many individuals regularly use multiple social media platforms, and their information exposure is shaped by the various networks they maintain across these platforms. Given the rising trend of multi-platform social media use, this article introduces a two-step approach to investigate how networks across platforms conjointly and distinctly relate to incidental exposure to news and political information. Our analysis of survey data from the United States showed that greater immersion in multiple politically heterogeneous networks across platforms predicted higher counter-attitudinal incidental exposure, while greater immersion in multiple politically homogeneous networks across platforms predicted higher pro-attitudinal incidental exposure. Among the popular platforms, immersion in networks on Facebook, X (Twitter), and YouTube played a particularly influential role in these relationships. Surprisingly, we also found that greater immersion in homogeneous networks across multiple platforms predicted higher counter-attitudinal exposure, even though immersion in any single platform’s homogeneous network was not a significant predictor.