Based on recent theories of affect and cognition, this unobtrusive field experiment predicted and found that induced positive mood improved real-life customer service behaviors by less experienced sales staff, but had no effect on the behaviors of experienced long-term staff in several department stores. Positive or negative mood was unobtrusively induced in sales staff in major department stores by a confederate. A second confederate, blind to the mood induction, then asked employees for help to locate a non-existent item. The frequency and duration of helpful behaviors in response to the request was recorded. Consistent with Forgas' Affect Infusion Model (AIM), less experienced employees showed a significant mood-congruent pattern in their responses helping more in a positive than in a negative mood. Long-term employees who could rely on routine, direct access processing were not influenced by the mood induction. The implications of these findings for contemporary affect-cognition theorizing and for everyday affective influences on interpersonal behaviors and customer service delivery are considered. Copyright © 2007 John Wiley & Sons, Ltd.