Thomas Kude, from University of Bamberg, will present his research. 

Counter-Orchestration in Platform Ecosystems: How Complementors Forced Apple into Changing Platform Rules

Platform owners with substantial market power can impose platform rules with unfavorable terms on complementors, while restricting typical market-based strategies for opposing or circumventing those rules. Yet, while complementors may have limited recourse against unfavorable terms in the market domain, platform owners also operate within broader social and political contexts, rendering them vulnerable to non-market challenges—ranging from public advocacy campaigns to regulatory interventions. This study explores how complementors can leverage non-market strategies to instigate platform rule changes in their favor. Drawing on a historical analysis of Apple's iOS ecosystem from 2009 to 2024, we reconstruct how complementors used non-market strategies to pressure Apple into changing key rules. From our extensive body of primary and secondary source material, we develop a process model of complementor-driven platform rule change that highlights the pivotal role of large, influential complementors—referred to as "complementor giants"—in orchestrating these changes. Specifically, the model identifies three interlinked mechanisms (Collective Action Cycle, Exposure Cycle, Long-Term Accumulation Cycle) that unpack how these giants, by deliberately designing and timing their non-market attacks, spark reinforcing responses from ecosystem participants (complementors and users), external stakeholders (regulators and media), and the platform owner, thereby creating mounting pressure for rule change. By offering a process-based explanation of complementor-driven rule change, our model advances (1) platform governance research by broadening the focus beyond owner-led orchestration to encompass counter-orchestration by complementor giants and (2) research on complementor mitigation strategies by moving beyond the notion of adaptation within owner-set rules to theorize how complementors can challenge and overturn those rules altogether. We moreover contribute to the wider non-market strategy literature by showing how the effectiveness of such approaches is closely tied to the specific tensions created by the platform owner's dual role as regulator and market participant.