Enterprise Social Networks continue to be adopted by organisations looking to increase collaboration between employees, customers and industry partners. Offering a varied range of features and functionality, this technology can be distinguished by the underlying business models that providers of this software deploy. This study identifies and specifies the different business models through an analysis of leading Enterprise Social Network providers: Yammer, Chatter, SharePoint, Connections, Jive, Facebook and Twitter. A key contribution of this research is the identification of consumer and corporate models as extreme approaches. These findings align well with research on the adoption of Enterprise Social Network that has discussed bottom-up and top-down approaches. Of specific interest are hybrid models that wrap a corporate model in a consumer model and may, therefore, provide synergies on both models.