The last few years have seen a flurry of persuasive technologies aiming to encourage pro-environmental behaviors. In this study, I critique the dominant means of persuasion by operationalizing and applying the lessons of a robust body of psychology research on values, specifically exploring the kinds of values accommodated by and appealed to with these technologies. Results indicate that these designs overwhelming appeal to Self-Enhancement values, the same strategic approach associated with historically unsuccessful environmental and social campaigns. This insight is used as a springboard for discussion about a radically different, and thus far untried strategy for addressing the challenge of sustainability within persuasive technology research and sustainable HCI more generally.