Revision with unchanged content. Shorter product life cycles, high product flop rates and an increasing heterogeneity of consumer needs have recently put considerable pressure on the innovation activities of manufacturers. The collaboration with users in open innovation processes has been promoted as a powerful approach for companies to succeed in today’s competitive environment. However, little is known about what drives these user innovators to contribute their time and effort to the creation of new products. Yet, a deep understanding of the motivation of user innovators represents an important first step for manufacturers to improve the nature of this type of cooperation. Robert Motzek’s study investigates the motivational profiles of user innovators from a manufacturer’s point of view. Since lead users and tool kit users can to a very high extent be involved in the firm’s innovation process, this report will focus on the integration of those two types of users. The analysis will be supported by two exploratory case studies of Spreadshirt and Threadless, two companies which have successfully based their business models on the integration of user innovators. The study will identify the most important factors controlling user innovators’ motivation and will derive suggestions on how manufacturers can address these points in order to tap the full potential of user innovation for their new product development.