This study explores how emotional arousal varies during service encounters and its impact on customer approach response. Drawing from psychology literature, the research identifies patterns in arousal variation and predicts how they affect customer behavior, such as spending and unplanned purchases. Field studies in two stores used electrodermal activity (EDA) to measure arousal over time. The findings show that the highest arousal level reached during an encounter and the skewness of arousal distribution predict customer approach response. The peak arousal level positively influences customer behavior, while a positively skewed distribution (more frequent lower arousal levels) decreases it. The end and trend in arousal levels did not show significant effects. The study contributes to customer experience literature by highlighting the dynamic nature of emotional arousal and its role in shaping customer responses. It also advances methodological approaches by using EDA to capture arousal in real-time during service encounters. The research suggests that service managers should design encounters to minimize low arousal moments and maximize high arousal moments to enhance customer approach response. Managerial implications include the need to consider emotional arousal when managing customer experiences, using real-time data to optimize service encounters. Future research should explore the effects of negative arousal and refine methods for capturing emotional valence.This study explores how emotional arousal varies during service encounters and its impact on customer approach response. Drawing from psychology literature, the research identifies patterns in arousal variation and predicts how they affect customer behavior, such as spending and unplanned purchases. Field studies in two stores used electrodermal activity (EDA) to measure arousal over time. The findings show that the highest arousal level reached during an encounter and the skewness of arousal distribution predict customer approach response. The peak arousal level positively influences customer behavior, while a positively skewed distribution (more frequent lower arousal levels) decreases it. The end and trend in arousal levels did not show significant effects. The study contributes to customer experience literature by highlighting the dynamic nature of emotional arousal and its role in shaping customer responses. It also advances methodological approaches by using EDA to capture arousal in real-time during service encounters. The research suggests that service managers should design encounters to minimize low arousal moments and maximize high arousal moments to enhance customer approach response. Managerial implications include the need to consider emotional arousal when managing customer experiences, using real-time data to optimize service encounters. Future research should explore the effects of negative arousal and refine methods for capturing emotional valence.