This study investigated post-transaction communications to improve direct marketing effectiveness. It presents a survey of relevant literature along with an empirical field study. The research design employed five levels of the independent variable: no post-purchase communications (control condition), an impersonal form letter expressing appreciation for the customer's patronage (with and without a discount offer), and an identical letter, but personalized (with and without a discount offer). It was found personalized post-transaction communications significantly reduced the number of orders returned for a refund. However, only the personalized letter with the discount offer produced significant increases in reorders.