Social marketing and the challenges of participant recruitment.

Recruitment of research participants often has not obtained a desired sample size, thereby becoming a major problem inhibiting investigators' ability to adequately test the specified hypotheses. Social marketing with its four Ps, originally developed by the business world to sell products and adapted for public health initiatives, is proposed as a dynamic comprehensive conceptual framework to apply marketing principles and practices to enhance participant recruitment. Applying a social marketing approach to research recruitment would require initial investigation to understand the motivations of the target audience in regard to research participation, and continued research throughout the main project to adapt the recruitment efforts as limitations arise.