This paper analyzes how specific aspects of design and governance of platform explain complementors participation in the video game console industry. This study introduces a new dimension to measure platform openness and suggest that by opening the platform vertically to different markets, platform firms can smoothen complementors competition and incentivize them to participate in their network. This study makes a first attempt to measure platform boundary resources and highlight its positive influence on complementors participation. Finally, the analysis also explores conditions under which signing an exclusive contract is beneficial for complementors. Complementors tend to participate in exclusive contracts during the early stages of platform rather than mature stages due to intense competition among complementors in the latter stage. The results suggest that by following the correct design and governance strategies, platform firms can orchestrate a large network of complementors and proliferate a variety of complementary product offerings.