We conduct a field experiment in China, o↵ering small business owners a conditional social media advertising subsidy. Beyond boosting business revenue and employment, the inter-vention significantly increases access to fintech credit: treated firms are more likely to open online stores and obtain online loans, while bank credit remains una↵ected. Our findings reveal a “fintech accelerator” mechanism—digital marketing drives sales growth that directly improves firms’ eligibility for fintech lending—demonstrating how targeted digital interven-tions can enhance financial inclusion and reshape credit allocation for small businesses.