The objective of this study is to assess whether shelf life, as indicated by the processor “sell by” date, influences product attractiveness, willingness to purchase and willingness to pay for organic and conventional milk—controlling for the effect of the milk production system. A completely randomized factorial between-subject design is combined with GLM-based ANOVA to assess mean differences for production systems and shelf life values. Experimental results indicate that consumers value the production system. However, consumers also indicated that they value the length of shelf life only after being prompted. Assessment of this attribute provides information relevant to product development and in-store marketing practices, although additional study of this issue appears merited.