Organizations employ Enterprise Social Networks (e.g. Yammer) expecting better intra-organizational communication, effective knowledge sharing and in general, greater collaboration. Despite their similarities with Public Social Networks (e.g. Facebook), Enterprise Social Networks are struggling to gain credence with employees. This paper is part of a larger research project that investigates mechanisms to enhance employees’ engagement in the Enterprise Social Networks. Through the lens of Control Theory, this paper reports preliminary findings of a pilot case study aimed to propose formal and informal mechanisms that impact employees’ intrinsic and extrinsic motivations to enhance the use of Enterprise Social Networks. The study results highlight (i) the need to better understand employees’ extrinsic and intrinsic motivations to use Social Networks, and that (ii) unlike a Public Social Network which acts as a hedonic system, an Enterprise Social Network acts as a utilitarian system, highlighting the importance of supporting intrinsic motivations in its implementation.