This chapter opens Part I of the book, focusing on social media as a digital participatory space. It examines the relationship between the state and platform firms in social media governance over two consecutive leaderships. It firsts map the landscape of social media platforms in China and the variety of participatory spaces they offer. Based on survey data, it identifies two platform companies that have evolved into important players in managing social media platforms with a significant reach in political information – Tencent and Sina. It then examines the significant changes in social media governance over two consecutive leaderships. Under Hu, social media governance was characterized by loose command and control with many choices for users, while popular corporatism emerged at the end of the Hu Jintao leadership and took off under Xi Jinping. Based on procurement data, the chapter elaborates on the state’s reasoning to rely on Tencent and Sina as the only corporations with the expertise and resources to provide key services in managing online public opinion. Its findings demonstrate that under popular corporatism large platform firms can leverage their superior expertise, data, infrastructure, and reach to gain concessions from the state due to their consultant and/or insider status.