Impact factors are nonspecific psychotherapeutic variables that refer to treatments' ability to overcome clients' tendency to disregard, neglect, or forget them. A scale was developed to assess impact factors in the field of smoking cessation. It was validated on 76 studies that included 210 treatment groups. Its two component subscales measure treatment elements that aim at overcoming clients' potential disregard by means of: a) Drama, surprise, arousal, and special states of consciousness (Special-States Scale), and b) effort expenditure, commitment, and directness of approach to problem (Activism Scale). These subscales succeeded in partially predicting treatment success, showing that the impact factors are promising nonspecific variables in psychotherapy research and practice.