This paper analyzes digital platforms’ business models, the reasons for their success and the challenges they present. Digital platforms offer an online forum for conducting transactions and therefore are able to dramatically reduce transaction costs, which creates value for platform users. Generally, digital platforms are aware of the high and increasing importance of data. By collecting and combining data from the different user groups, digital platforms are able to improve their service for existing users and to attract new user groups. Digital platforms’ market power and their control over large, valuable sets of data have attracted the attention of regulatory authorities and led to investigations and fines. Economic policy should aim to protect consumers while still fostering the digital platform business model.