This chapter reports on the crowdfunding phenomenon and expounds its principles, trends and issues. Based on analyses of primary and secondary French data, we illustrate and discuss the recent academic literature on crowdfunding. We stress the relationships between crowdfunding and crowdsourcing. The advantages and disadvantages of crowdfunding are also presented. We show that crowdfunding is an ecosystem still under construction. We rely on ‘multisided platform theory’ to explain the strategies implemented by competing platforms and give some prescriptions to mobilize a crowd and to finance a project successfully.