Honey is a Chrome extension that makes it much easier to find coupons and promo codes and Mozilla also has a version of it as an Add-on. The extension/add-on works thusly: It adds a button to your checkout page. You click this button and the extension searches for and applies the coupon codes to your order. You can take a look at some reviews of the add-on here: Please Log In to view this link! Can be great especially if you don't have the time to search for coupons and promo codes.