This chapter analyses how the concept of ‘sharing’ relates to the smart city paradigm. Theories on ‘sharing’ and on smart cities have discursive resemblances, as both seek to connect communities, to empower residents and to promote the efficient use of resources. However, if we look at the actual practice of what is known as ‘sharing’, rather than taking the prescriptive perspective of what it ought to be, this practice may contradict its original inspiration and, therefore, the purpose of smart cities. The chapter will look at the origins and development of Uber and Airbnb, analyse their growth dynamics as ‘multisided platforms’ as well as their influence on incumbents and their negative externalities. The conclusion is that platforms rely on secrecy as a strategic weapon, and that they disempower citizens by contributing to the commodification of their neighbourhoods.