1 Broadcasting in Online Social Networks: An Empirical Study of Music Sales and Artists ’ Activities

2 This paper examines artists ' broadcasting behaviors on social networking sites and the relationship between broadcasting behaviors and music sales. We employ a panel vector autoregressions (PVAR) model to analyze a dataset containing the activity stream data from MySpace and music sales data from Amazon. This model allows us to study the interactions between artists ' promotional activities and music sales and to estimate the effect of a shock to one variable on another variable. We find empirical evidence that intense broadcasting behaviors on MySpace could lead to an increase in music sales and that artists tend to broadcast more when they have higher music sales in previous periods. Between the two types of broadcasting activities on MySpace, we find that friend updates are more effective in promoting sales than bulletins. The number of friends for artists also largely affects the effectiveness of promotions as the impact of friend updates on music sales is much larger and more significant for artists with more friends. 3 1