In this paper we explore the persuasive effects of social feedback, as provided by an embodied agent, on behavioral change. In a lab setting an experiment was conducted in which participants had the opportunity to conserve energy while carrying out washing tasks with a simulated washing machine. The experiment tested the effect of positive and negative social feedback and compared these effects to more widely used factual feedback. The robotic source, a so-called iCat, was manipulated with regard to its perceived agency. The results showed an effect of social feedback compared to factual feedback. In addition an effect of feedback valence was found, demonstrating more conservation actions following negative social feedback. The predicted perceived agency effect could not be demonstrated