This chapter examines the predictive features that digital platforms make available to marketing and advertising professionals to create and manage digital advertising campaigns. In a series of interviews, digital marketing practitioners provide an account of the state of the art of predictive analytics: in which processes intervene, how reliable they are and to what extent they have been adopted by professionals. Despite the fact that digital platforms provide sophisticated tools to make data available, automate processes and forecast performance, these tools are not seen as precise as they are depicted in popular culture. On the contrary, even though professionals acknowledge that they are increasingly accurate in their predictions and can outperform humans in many areas for managing ad campaigns, they also identify several limitations on the tools and techniques that digital platforms make available to them.