Discounts and coupons are used to increase repeat sales and get customers back into the store. But just sending coupons to all your customers can be less effective and can even yield negative results. In order to maximize the effectiveness, you need to send it to the right customer at the right time. For example, you can send a coupon to customers who have not purchased during the past 90 days, offering an incentive to come back. This marketing tactic, called Email Remarketing, is used by ecommerce retailers to leverage their existing relationships with customers in order to increase repeat sales.