Stefan R. Thallmaier’s investigation enables mass customization businesses to better understand how co-design increases customers’ value perception. He focuses on the increasing proliferation of service channels (online, mobile and in-store) and digital media (toolkits, social media and live help) at the co-design interface. Based on qualitative and quantitative research, the author examines how this proliferation impacts customers’ value perception in the different stages of the co-design process. The research shows that customers’ value perception profits from varying levels of social presence throughout the co-design process. The work helps researchers and practitioners with surprising insights as well as hands-on recommendations to improve and adapt interfaces for customer co-design.