Online reviews have a profound impact on firms’ pricing and quality strategies. However, consumer self-selection bias may distort review information and mislead firm’s decisions. This paper incorporates consumer self-selection into the review-generation process and develops a two-period dynamic model to study firms’ optimal product line design and pricing decisions. It compares three informational environments: No reviews, objective (unbiased) reviews, and reviews subject to positive or negative self-selection bias. The analysis yields several insights. First, objective reviews do not affect initial product introduction decisions, whereas biased reviews systematically distort firms’ subsequent choices: Negative bias induces higher quality and lower prices, while positive bias leads to the opposite response. Second, optimal product line strategies depend jointly on the direction and magnitude of review bias, product experience quality, and production costs. Third, the welfare effects of online reviews are non-monotonic. Depending on cost and bias conditions, reviews may either improve both firm profits and consumer surplus or exacerbate conflicts between them. A win-win outcome arises only when negative bias is sufficiently weak or when bias is positive and production costs are relatively high. Overall, this study clarifies how biased online reviews reshape firms’ dynamic product decisions and offers insights into pricing, quality iteration, and review management.