Resumen
The paper provides empirical evidence supporting the assumption that content plays a critical role in determining the virality, i.e., the influence, of social media information. The analysis focuses on multimedia content on Twitter and explores the idea that links to multimedia information increase the virality of posts. In particular, we put forward the following three main hypotheses: (1) posts with a link to multimedia content (photo or video) are more retweeted than posts without a link; (2) posts linking a photo are more retweeted than posts linking a video, and (3) posts linking a video raise more sentiment than posts linking a photo. Hypotheses are tested on a sample of roughly two million tweets posted in July 2011 including comments on Berlin, London, Madrid, and Milan relevant from a tourism perspective. Findings support our hypotheses and indicate that multimedia content plays an important role in determining not only the volumes of retweeting, but also the dynamics of the virality of posts measured as speed of retweeting.