For health, safety, and economic reasons there is a critical need for novel approaches to enhance the retention of new blood donors. The current study examines an innovative, theory-driven approach to retention by promoting intrinsic motivation to donate again among new blood donors. Self-determination theory (SDT) proposes that people are more likely to persist with behaviors that are internally versus externally motivated, and considerable research supports the notion that more internalized motivation is associated with better adherence in a variety of health contexts. Similar findings have also been reported in the blood donation context where measures of the extent to which a donor identity has been internalized are positively related to both donation intention and future donation behavior. Based on prior work, the investigators propose to test a multi-component intervention designed to enhance one, two, or all three of the fundamental human needs that contribute to internal motivation according to SDT (i.e., competence, autonomy, relatedness). Using a full factorial design, first-time donors will be randomly assigned to a control condition or an intervention that addresses one, two, or all three of the fundamental needs. The primary aim is to determine whether the intervention conditions, alone and in combination, increase the likelihood of a donation attempt in the next year. The second aim is to examine intervention-specific increases in competence, autonomy, and relatedness as potential mediators of enhanced donor retention. Finally, an exploratory aim will examine an integrative model of motivation that views autonomy as a mediating influence on the more proximal, situational-level determinants of behavior (i.e., attitude, subjective norm, perceived behavioral control, and intention).