Abstract: The diffusion of social networks platforms opened the door to a new age of peer to peer distributed advertising content widely referred to as viral advertising. The current study proposes a social networks approach to the study of viral advertising. Expanding beyond the conventional retweets metrics to include Twitter mentions as connection in the network, this study identifies three groups of key users: Hubs – highly retweeted users, Bridges – highly mentioned users connecting otherwise primarily disconnected users, and Isolates – low influence users. The role that each of these users in viral advertising is discussed and illustrated by a case study of Heineken’s Worlds Apart campaign. We discuss the contribution of the network approach in the context of the growing body of literature on this relatively new advertising strategy examining, key variables that may lead to the success of social media advertising campaign.