Users play an important part in innovation processes and outputs. Both firms and consumers have needs that must be understood for a product to stand any chance of success. They also possess expertise that is potentially valuable for product development. Users may even modify existing products or develop new ones in response to their own needs, possibly anticipating future market demand in the process. However, despite a large body of literature exploring these and other aspects of user involvement in innovation, we still know relatively little about the scale and importance of these activities. This study is the first to explore user innovation amongst a large sample of European firms engaged in innovative activities. It provides new insigh...