  From its origins in the mid 90s, the application of the concept of virality
to commercial communication has represented an opportunity for brands to cross
the traditional barriers of the audience concerning advertising and turn it
into active communicator of brand messages. Viral marketing is based, since
then, on two basic principles: offer free and engaging content that mask its
commercial purpose to the individual and using a peer-to-peer dissemination
system. The transformation of the passive spectator into an active user who
broadcasts advertising messages promoted by sponsors, responds to needs and
motivations of individuals and content features which have been described by
previous research in this field, mainly through quantitative methods based on
user perceptions. This paper focusses on those elements detected in its
previous research as promoters of the sharing action in the 25 most shared
viral video ads between 2006 and 2013 using content analysis. The results
obtained show the most common features in these videos and the prominent
presence of surprise and joy as dominant emotions in the most successful viral
videos.
