Resumen
In light of the increasing importance of Social Networking Sites (SNSs) for both personal and professional relationships, the aim of this work is to contribute to the knowledge framework regarding the interactive behaviour of Internet users, particularly within Web 2.0, describing its evolution from Web 1.0. Moreover, this paper analyses the different behaviours on the Web by people who use or not use SNSs, as well as to determine whether any such differences are significant in order to discover the reasons why these people participate. As results, initial characterization of the users themselves is followed by an analysis of the main differences between users and non-users of these applications. With this information, companies can play an active role in this Social Web by becoming company 2.0 and participating actively in already existing SNSs or creating their own social network service.