Persuasion is a fundamental aspect of how people interact with each other. As robots become integrated into our daily lives and take on increasingly social roles, their ability to persuade will be critical to their success during human-robot interaction (HRI). In this article, we present a novel HRI study that investigates how a robot's persuasive behavior influences people's decision making. The study consisted of two small social robots trying to influence a person's answer during a jelly bean guessing game. One robot used either an emotional or logical persuasive strategy during the game, while the other robot displayed a neutral control behavior. The results showed that the Emotion strategy had significantly higher persuasive influence compared to both the Logic and Control conditions. With respect to participant demographics, no significant differences in influence were observed between age or gender groups; however, significant differences were observed when considering participant occupation/field of study (FOS). Namely, participants in business, engineering, and physical sciences fields were more influenced by the robots and aligned their answers closer to the robot's suggestion than did those in the life sciences and humanities professions. The discussions provide insight into the potential use of robot persuasion in social HRI task scenarios; in particular, considering the influence that a robot displaying emotional behaviors has when persuading people.