Abstract: | Innovation contest communities are virtual tools for corporations to integrate external knowledge and creativity into the innovation process. Built on both the principle of competition and the advantages of a collaborative community, innovation contest communities constitute special interaction phenomena. The present study explores how different co‐operation behaviours, namely reciprocal giving, initial altruistic giving and free‐riding, influence the quality of participants' ideas on an open virtual contest platform with more than 2,000 members and more than 4,000 submissions. Our findings show that reciprocity and free‐riding are substantial behavioural elements of innovation contest communities leading to different outcomes regarding quality of submitted ideas. With this study, we contribute to a better theoretical understanding of distinctive types of co‐operation and free‐riding among individuals in the context of open innovation, extending theories of the evolution of co‐operation. |