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 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 the volumes of retweeting.