In this article, I utilize a unique collection of auctions on eBay to study the influence of seller reputation on auction outcomes. In a market of homogeneous goods with non-enforceable contracts, I find that sellers who improve their reputation by one quintile from the lowest, experience a 6.2% higher probability of sale and a 6.1% hike in valuation after adjusting for truncation bias from failed auctions and explicitly controlling for unobservable seller heterogeneity. This study also shows that in addition to a dimension of reputation universal across different product markets, the product-specific dimension of reputation significantly affects the auction outcomes.