It works so well for Amazon and it could work for your site. Allowing customers to redeem gift certificates and coupons in your store is a great way to attract repeat visitors. You can notify customers about coupons via e-mail, from your web site or other advertising. For example, you can send a £5 Gift Certificate to all customers that have bought more than £100 of products in the last year to encourage them to purchase again. Or you can reward customers who spend more than £75 at your site by giving them a 10% discount on their next purchase.