Trust and credibility are critical factors in peer-to-peer (P2P) service platforms such as Airbnb and Turo, where consumers must make decisions with limited information. Writing a bio serves as a potential mechanism to reduce uncertainty and foster a stronger connection with prospective customers. However, existing research has not examined the impact of bios on service provider ratings in online P2P marketplaces. Leveraging a dataset of 264,810 unique listings across 31 U.S. cities, this study employs a series of double-censored Tobit models to investigate the effect of writing a bio on host ratings. Our findings reveal that having a bio significantly enhances host appeal, particularly for professional and male hosts, while its impact is less pronounced for hosts who have already attained formal recognition. These results underscore the role of self-disclosure in trust-building, bias reduction, and consumer decision-making in P2P business platforms. Our study has several theoretical and practical implications.