The last decade has witnessed the proliferation of crowdsourcing in various academic domains including strategic management, computer science, or IS research. Numerous companies have drawn on this concept and leveraged the wisdom of crowds for various purposes. However, not all crowdsourcing projects turn out to be a striking success. Hence, research and practice are on the lookout for the main factors influencing the success of crowdsourcing projects. In this context, proper governance is considered as the key to success by several researchers. However, little is known about governance mechanisms and their impact on project outcomes. We address this issue by means of a multiple case analysis in the scope of which we examine crowdsourcing projects on collaboration-based and/or competition-based crowdsourcing systems. Our initial study reveals that task definition mechanisms and quality assurance mechanisms have the highest impact on the success of crowdsourcing projects, whereas task allocation mechanisms are less decisive.