The article highlights the risks of using self-evaluation as a substitute for primary and secondary market research when designing and monitoring marketing programs. Included is a study of 110 management teams that suggests internally dominated marketing analysis may breed illusory evaluations of a company's own marketing programs versus competitors. If acted upon, such illusions could lead to oversights in developing marketing offerings. The overriding potential implication of the study addresses the allocation of a company's substantial marketing assets—most notably, the risks of bypassing secondary market data and primary market research when developing and evaluating marketing programs. © 2001 John Wiley & Sons, Inc.