Mobile Internet services are offered by complex ecosystems, which are difficult to control. While control theory has been applied to traditional forms of interorganisational software development, it is yet unclear how input, behavioural and output control should be used to manage complex ecosystems. This paper analyses the impact of a portfolio of ecosystem control mechanisms on a set of performance criteria through a survey. We find that ecosystem leaders manage dependencies among partners through a combination of outcome and behavioural control. In contrast, access to complementary resources is achieved through input and behavioural control. The ecosystem leaders also safeguard customer relationships from other partners through a combination of outcome and behavioural controls. The study extends traditional control theory towards the emerging realm of platform-based mobile service development.