With the rapid growth of social media platforms, short video advertisements (SVAs) have been a dominant channel for product sales. However, how to design SVAs that effectively drive product sales, especially in relation to previous SVAs and the related product information, remains underexplored. This study investigates how SVA title congruence influences sales performance through the mediating role of sociability. Specifically, we conceptualized video-video title congruence and video-product title congruence as two forms of content congruence and investigated their effects using data collected from Douyin, the leading short video platform. The empirical results with two-way fixed effects show that high video-video title congruence and low video-product title congruence are both associated with higher product sales. Sociability mediates the relationship between title congruence and sales performance. This study also finds that the creation frequency and product brand significantly moderate these relationships. Furthermore, this study develops several checks to ensure the robustness of the research model and findings, including the Heckman two-stage test. These findings provide theoretical insights into content creation strategies and offer practical implications for both creators and platform managers.