Research on aggression from organizational outsiders (customers, clients or patients) has ignored insider-instigated aggression, and has been limited to employees in emotional labor jobs (e.g., social work and customer services). The authors argue that customer-employee interactions have distinct characteristics from organizational insider interactions, and provide two studies to compare the frequency and strain of verbal abuse from customers, supervisors and coworkers. Furthermore, they assess whether customer verbal abuse is only a critical issue for employees in jobs requiring emotional labor, measured with both O*NET job codes and self-reported display rules. With a national random sample of U.S. employees (n = 2446) and a convenience sample of U.S. employees who have customer contact (n = 121), the authors find that verbal abuse from outsiders (1) occurs more frequently than insider verbal abuse, particularly for those with higher emotional labor requirements, and (2) predicts emotional exhaustion over and above insider verbal abuse, regardless of emotional labor requirements. The authors conclude that better integration of customer aggression and insider aggression research is needed. (c) 2007 APA, all rights reserved.