The paper explores the role of internal social capital in attracting early contributions to crowdfunding campaigns, which are crucial for their success. The authors argue that early contributions play a self-reinforcing role, and that internal social capital, developed within the crowdfunding community, is a key factor in attracting these early contributions. Using an econometric analysis of 669 Kickstarter projects, they find that internal social capital positively influences both the number of early backers and the amount of early capital, which in turn mediates the success of the campaign. External social capital, such as connections with family and friends, also affects early contributions but to a lesser extent. The study highlights the importance of mutual identification, reciprocity, and the social connections formed within the crowdfunding platform in driving early support.The paper explores the role of internal social capital in attracting early contributions to crowdfunding campaigns, which are crucial for their success. The authors argue that early contributions play a self-reinforcing role, and that internal social capital, developed within the crowdfunding community, is a key factor in attracting these early contributions. Using an econometric analysis of 669 Kickstarter projects, they find that internal social capital positively influences both the number of early backers and the amount of early capital, which in turn mediates the success of the campaign. External social capital, such as connections with family and friends, also affects early contributions but to a lesser extent. The study highlights the importance of mutual identification, reciprocity, and the social connections formed within the crowdfunding platform in driving early support.