Within the field of nutrition education, social marketing has become a promising framework to systematically approach problems related to nutrition behavior. In 1997, the Colorado Nutrition Network began developing a social marketing campaign to promote healthful food choices among low-income Coloradans. A multifaceted formative evaluation plan that included focus groups, campaign concept pretesting, and a food frequency questionnaire was used to segment and scrutinize the target audience. The resulting pilot program was a blend of educational and marketing strategies targeting preschoolers that was implemented in Head Start classrooms. The 12-week intervention contained a narrow, behavior-based "try new foods" message, multiple nutrition education activities, and repeated opportunities to taste 13 novel foods. Key strategies used and findings from the formative evaluation process are presented herein in an effort to provide insight for nutrition educators interested in developing similar interventions.