The aim of the paper is to analyse the features of the digital labour connected with the so-called platform economy. Many platform-based business models rely on a new composition of capital capable of capturing personal information and transforming it into big data. Starting with the example of the Facebook business model, we explain the valorisation process at the core of platform capitalism, stressing the relevance of digital labour, to clarify the crucial distinction between labour and work. Our analysis differs from Fuchs and Sevignani’s thesis about digital work and digital labour and seems consistent with the idea that Facebook extracts a rent from the information produced by the free labour of its users.