On the Limits to Multi-Modal Popularity Prediction on Instagram -- A New Robust, Efficient and Explainable Baseline

The predictability of social media popularity is a topic of much scientific interest and significant practical importance. We present a new strong baseline for popularity prediction on Instagram, which is both robust and efficient to compute. The approach expands previous work by a comprehensive ablation study of the predictive power of multiple representations of the visual modality and by detailed use of explainability tools. We use transfer learning to extract visual semantics as concepts, scenes, and objects, which allows us to interpret and explain the trained model and predictions. The study is based in one million posts extracted from Instagram. We approach the problem of popularity prediction as a ranking problem, where we predict the log-normalised number of likes. Through our ablation study design, we can suggest models that outperform a previous state-of-the-art black-box method for multi-modal popularity prediction on Instagram.