Coupon help us to give additional discount on selling price and we have choice to limit our buyers and date for discounts. Coupon proved to be great help to liquidate less selling products and increase sales during holidays. Coupon cost extra few cents for each redemption.
Creating promotions was first technique to increase conversion rate but due to its location very few people even come to know that a promotion is running on a product. Although, this technique urge a buyer to purchase more than 1 or more quantities at a time.There is no extra cost after promotional offer.
Deal: Amazon decides list of ASINs for deal. Sometime, Amazon will send separate email on your registered email id for upcoming events. Deals help to sell products in quantities in limited period. There may be extra cost for each deal submitted apart from discount offered.