Digital platforms mediate increasingly more activities, from shopping and reviewing products to income-generating work, in which users rely on platform features and interact with strangers in cyberspace. Surprisingly, little is known about users’ experiences of motivation states during a specific digital task, despite motivations being a driver of human behaviors such as digital content-generation, which is fundamental to sustaining these platforms. Applying self-determination theory, the dissertation provides an overview of the IS motivation literature, before conducting two empirical studies in different use contexts. The first study involves a non-instrumental platform used to support online reviews, which is usually a voluntary task that is not considered an income-generating activity. The second context is an instrumental platform where people work on microtasks for money. The results show that in these two use contexts that differ in instrumentality, some motivation states are more dominant than others, and have different influences on behavioral outcomes. Further, the studies show that artifacts which give meaning to digital activities can facilitate motivation internalization and result in more desirable behaviors. Theoretical and practical implications of the findings are then discussed to conclude the dissertation.