Antitrust oversight is crucial for maintaining vibrant competition. Evaluating mergers of platforms carrying digital content such as the proposed merger of XM and Sirius, however, poses new challenges for antitrust officials. In particular, companies like these are platforms in two-sided markets that must find ways to attract subscribers and content. Both subscribers and content providers can choose among a variety of platforms. Moreover, the platforms themselves are dynamic in that they could potentially carry any digital information, not just the particular services they currently offer.
In short, a merger analysis of competing platforms that considers only a single component in this complex market is likely to reach an incorrect conclusion. In the case of the XM-Sirius merger, officials should consider not only subscribers, but also content providers, competing platforms, platforms that are potential competitors, and services the platforms in question may provide in the future that they do not today.