This paper summaries the authors' experience in estimating the sales impact of product quality improvements, made to new products. The paper describes the manner in which a particular forecasting technique takes account of product evaluation in its estimation process, and clarifies the specific components of sales affected by product quality. Case history material is shown to demonstrate the sales impact of product improvement. Four specific points are highlighted. First, the importance of high product quality in launching new brands. Second, the impact on sales that variance in product quality can have. Third, that the sales impact generated by product improvements can be estimated pre-launch. Fourth, that pre-test market systems can, and should, be used as diagnostic tools to evaluate product change.