Hospitality exchange (HospEx) networks – online platforms facilitating the connection between a traveler and a local resident – embody many of the cyber-utopian promises intrinsic to the Web as it started out 25 years ago. Such sites have often been conceptualized as a new and daring trend in a booming ‘sharing industry’ and have been researched for topics such as trust, reputation, and online identities. Yet, a more critical look uncovers that crucial issues of ownership, power, digital labour, and organizational structures have often been left out. To fill this gap, this thesis investigates upon the antagonistic struggle between the commons and processes of commodification in the light of critical theory and political economy. The research shows that examples with characteristics of both concepts are manifested in the niche social networking space of HospEx platforms. The biggest of those platforms, Couchsurfing.org, changed its organizational orientation from a non-profit, commons-based project towards a for-profit company in 2011 – an instance of commodification. An analysis of both quantitative and qualitative community data shows that the transformation consequently concerns a member on multiple levels. The structural change of ownership results in a loss of transparency and privacy, an alteration of the platform’s integrity, a sacrifice of the ‘uniqueness’ of the community, and a differing relationship between the user and the platform. To shed light on an antagonistic force and suggest an alternative, community-based governance approach, the work further explores the specifics of a platform guided by the logic of the commons. Interviews with volunteers of the non-commercial, non-profit HospEx platform BeWelcome.org helped to deepen an understanding of how a digital commons can be sustained and what challenges they face. The thesis concludes that the developments observed on Couchsurfing are not an exception but rather characteristic and part of a broader trend manifested in all areas of digital media, and indeed modern society in general: commodification processes frequently jeopardize the commons and incorporate them into the logic of capital.