MFNs and other measures which can reduce customer incentives to switch, such as fidelity rebates, have long been a complex area of European and wider antitrust laws. There is a renewed focus on these clauses, given the prevalence of MFNs in two-sided digital platform markets, and the ECJ’s landmark decision in Intel. As regulators struggle to get to grips with the implications of the digital economy for competition law, different authorities, including within the EU, have taken seemingly contrasting approaches. This article seeks to evaluate the recent developments and shed some light on the current status. Finally, we ask whether the growing importance of big data, amassed in part by consumer-level loyalty programs, suggests a lacuna in the current EU and UK approach to dominance.