Thorsten Pieper explores the impact of innovation barriers along the user innovation process, in particular whether technological, social, legal and ownership barriers change the properties of user-developed products. This study roots from the “open innovation” research field and reveals insights from innovating users in “collaborative workspaces”. The results prove a hierarchical allocation of innovation barriers regarding their influence on the end-product and moderating influences of user innovators’ personal characteristics. The author discusses these insights and provides practical recommendations for more efficient promotion of user innovations and successful integration in corporate “co-creation” projects.