This document discusses evaluating the effectiveness of sales promotions. It begins by outlining common sales promotion techniques like money off deals, coupons, free gifts, and product sampling. The purposes and benefits of promotions are also reviewed, along with limitations. To evaluate effectiveness, the document recommends comparing sales before, during, and after a promotion using data from retailers and consumer surveys. Examples provided include a Coca-Cola promotion targeting loyal customers and an Auchan discount store promotion during a holiday. Proper evaluation is necessary to determine if promotions increase market share or attract unwanted "cherry pickers."