Like any well-run company deciding on what products and services to offer, a good library should pay attention to customer demand when it is building its business reference collection. What kind of information do business patrons want? Most are looking for company and industry details: a corporate address or name of an officer, financial data for a stock or mutual fund investment, a list of competitors or the key companies in a particular industry, or news articles on the trends in an industry or who has the biggest market share. This article discusses the process by which libraries decide how to build their business reference collection.