Evaluating the effect of viral news on social media engagement
Emanuele Sangiorgio, Niccolò Di Marco, Gabriele Etta, Matteo Cinelli, Roy Cerqueti, Walter Quattrociocchi
TL;DR
The paper addresses how viral posts affect user engagement on Facebook and YouTube, across four European languages, by applying a Bayesian structural time-series (BSTS) based comparative interrupted time-series (CITS) framework to post-viral engagement windows. It defines virality via a bivariate spreading and interactions metric, detects viral posts with platform-specific z-score thresholds, and evaluates impact with two research questions on growth and persistence. The key findings show that viral events are typically transient, often failing to produce sustained engagement, with a stronger boost when virality occurs as a sudden exogenous shock rather than after a prior growth phase; faster virality tends to fade sooner, while slower, sustained growth yields more persistent effects. The study highlights the elastic nature of collective attention and argues for continuous, steady engagement strategies over reliance on viral spikes, with implications for news outlets and social platforms alike.
Abstract
This study examines Facebook and YouTube content from over a thousand news outlets in four European languages from 2018 to 2023, using a Bayesian structural time-series model to evaluate the impact of viral posts. Our results show that most viral events do not significantly increase engagement and rarely lead to sustained growth. The virality effect usually depends on the engagement trend preceding the viral post, typically reversing it. When news emerges unexpectedly, viral events enhances users' engagement, reactivating the collective response process. In contrast, when virality manifests after a sustained growth phase, it represents the final burst of that growth process, followed by a decline in attention. Moreover, quick viral effects fade faster, while slower processes lead to more persistent growth. These findings highlight the transient effect of viral events and underscore the importance of consistent, steady attention-building strategies to establish a solid connection with the user base rather than relying on sudden visibility spikes.
