Recognizing this trend, marketers have begun leveraging social networking sites (e.g. MySpace, Facebook, LinkedIn, and Twitter) in order to generate awareness, interest, and ultimately product purchase. Their strategy typically involves creating product-related pages, and then attempting to drive potential customers to those pages through advertising and WOM (Green, 2008). Our research focuses on the factors unique to social networks that impact that WOM dissemination. Although previous studies contrasting traditional versus electronic (i.e. e-WOM) WOM have yielded conceptually useful models to explain the determinants of e-WOM influence (De Bruyn and Lilien, 2008; Litvin et al., 2008), ours is the first to examine how those findings may be moderated in a social networking setting.

We begin by describing several of the unique characteristics of social networking sites that distinguish them from other forms of online networks. We then discuss how the standard communication hierarchy of effects (HOE) model differs in these online social networks from what has been reported in traditional face-to-face or e-WOM settings (Frenzen and Nakamoto, 1993). Based on our discussion, we develop hypotheses to predict the effects of source and channel factors on how a consumer reacts to a persuasive WOM communication (i.e. within an online social network). Finally, we empirically test our hypotheses in the context of two of the most popular social networking sites – Facebook and Twitter.

Theoretical development

Online social networking sites

An online social networking site typically involves a collection of user profiles where registered members can place information that they want toshare with others. Users are generally involved in either creating new content (e.g. adding photos; writing messages) or consuming content that others create. On most social networking sites, users can add other users to their network of contacts. Typically one user initiates the invitation, and the other user accepts or rejects it. When accepted, the two profiles become linked.

The resulting network corresponds to what we refer to as a “Friend-Network”.

By default, the communication linkages that are established on most social networking sites (e.g. Facebook, LinkedIn) are bi-directional in nature. On others (e.g. Twitter), uni-directional linkages are established such that a user might receive information from some Friend Network members (i.e. “follow” those members), convey information to others, and interact bilaterally with yet a third Friend Network group.

In the case of business organizations, product pages (rather than inpidual member profiles) can be created, and users can then be invited to join those product pages in order to “follow” the products (i.e. which allows the users to receive and/or disseminate product-related information). We refer to a “Product Network” as the collection of users who have elected to join a particular product page.

What distinguishes online social networking sites (e.g. MySpace, Facebook, Twitter, LinkedIn, YouTube) from other, more generic web-based communities (e.g. Yelp, Hotmail, users providing product ratings on Amazon.com) is that WOM communication typically takes place between inpiduals who have some form of pre-existing personal relationship with one another, because both are members of the same Friend Network.

Even if that relationship is not “close”, it is possible for each inpidual to check the background of the other by examining his or her personal profile page. In other types of online communities, this background check is not possible.

In addition, online social networking sites are distinguished by the fact that they typically publish lists of those members who have elected to join the aforementioned Product-Network sub-groups. Thus, interest in (or liking of) a product becomes public knowledge. For example, depending on privacy settings, a list of those inpiduals who follow a particular Facebook product page (e.g. the restaurant, La Maison) is available to all site members, and the act of joining that Product Network is publicized through WOM in on-line social networks the inpidual member’s “News-Feed”[1]. Conversely, in a more generic online network such as Yelp, while members may be able to see that John Doe has given La Maison a five-star rating, that information is not automatically forwarded to a sub-group of friends. Further, everyone who rates La Maison does not automatically become a member of a separate Product (La Maison) Network.