We describe questions that commonly arise in early-phase user research for new technology products concerning customer needs, priorities, and market definition. We suggest that methods adopted from marketing research, statistics, and game theory may be helpful for user researchers to answer those questions. We show how these methods have been applied to real problems and decisions for a new product line at Microsoft. These methods are especially appropriate for HCI professionals because they require solid experience with experimental research and statistical methodology and complement other user research tools. The methods may be most effective when combined with detailed research on user tasks, goals, and interaction models. When research is synthesized in this way, it can make a strong contribution to product definition and business strategy.