In this study, we aim to explore the impact of the experiences of review providers, referred to as reviewers, on the usefulness of reviews based on the theory of source credibility. Specifically, we examine three dimensions of reviewer experience - product purchasing experience, review writing experience, and product usage experience - to validate their influence on the usefulness of reviews. We collected 443,432 reviews for 500 games from the online gaming platform, Steam, and analyzed the data using hierarchical regression analysis. The results revealed that reviewer's product purchasing experience and review writing experience positively affect the usefulness of reviews. However, in the case of product usage experience, reviews received high usefulness ratings when the experience was either low or high, whereas the usefulness rating decreased when the product usage experience was moderate, showing a U-shaped relationship. This suggests that by providing specific information about reviewer experiences from various aspects on the platform, users can more easily identify useful reviews, leading to an increase in the platform's value.