‘Classical’ media practices were difficult to observe, always requiring external tools and methods. Digital media fundamentally changed this situation. Media use and data production have converged, such that practices basically record themselves. Such practices have become what we call ‘data acting/trading‘. Using the example of online shopping, we discuss how software, interfaces and the media practices of users and providers interact. Thereby, we show the complex relations between the experiences of users as individuals, their role as prosumers, and their representation as data sets in a digital media environment.