PromoFinder is a web-based tool that analyzes YouTube channel video descriptions to identify sponsorship and affiliate marketing activity. The service scans public video descriptions from the last 12 months to uncover sponsors, affiliate programs, brand deals, and promo codes without requiring user registration or payment. The tool works by accepting any YouTube channel URL, @handle, or channel ID and processing the associated video descriptions to extract promotional content. Results are presented showing which brands appear in the channel's content, how frequently they are mentioned, and the data can be exported in CSV or JSON formats for further analysis. PromoFinder operates entirely on publicly available information, making it privacy-safe and compliant with YouTube's terms of service. The service focuses specifically on analyzing video descriptions rather than scraping private data or using grey-area techniques that might violate platform policies. The tool is designed for three primary user groups: creators researching their competition to understand what brands are sponsoring similar channels, brands hunting for potential partnership opportunities by identifying channels that work with complementary companies, and marketers conducting competitive intelligence to analyze promotional strategies in their industry. PromoFinder was created by solo developer David J Woodbury, who built the tool to solve his own pain point of manually digging through YouTube descriptions to figure out which companies were sponsoring channels in his niche. The service is completely free to use with no login requirements.