A substantial and growing body of research on coupons and coupon effectiveness has emerged in the marketing literature. The objective of this paper is to review and consolidate the findings of previous studies to provide a better understanding of the factors that influence consumer response to direct mail coupons. The effects of coupon, brand, product category, and consumer characteristics on redemption behavior and incremental sales are examined, and their implications for the effectiveness of direct mail coupon promotions are discussed. Based on the findings of prior studies, a theoretical model of coupon effects on purchase behavior is proposed. Several key issues that need to be addressed in future research are identified. © 1996 John Wiley & Sons, Inc.