The present paper aims at investigating the question of what drives individuals to share viral messages. Building on Self Determination Theory, we examine the impact of the individual’s need for autonomy, competence, and relatedness on forwarding intention. The results of our empirical study (n = 1,261) demonstrate that autonomy, competence and relatedness affect the intention to forward a viral message. The analysis of detailed forward behavior show that message forwarding to a rather uncontrollable audience is more strongly determined by the need for autonomy and relatedness, whereas message forwarding to a preselected group of people is rather determined by the need for competence.