Within the Discount Code Manager, you have the ability to create Discount Links and Free Shipping Discounts to your site that use a Cookie on your customer's computer to display discounted prices. The Discount Cookies will expire on the customer's machine one year after they click on the Discount Link. This Discount Cookie will remain on the customer's computer for one year or until they delete their cookies, whichever comes first.
Therefore, every time a customer returns to your site, if that Discount Code is still active within your Admin Panel, the return customer will receive the discounted prices.
This QuickGuide includes tips for managing your Discount Code Links that use Cookies.
To add or modify your Discount Codes go to Inventory >> Discount Code Manager. You will see the menu below:
In order to deactivate a Discount Link you can either uncheck the “Cookie” box or delete the discount entirely by clicking on the “Delete” button for the particular Discount Code that you want to remove.
Once a Discount Link is deactivated, visitors that access your site through that link will not receive discounted prices on any items added to their carts.
If any customers have come to your site through a Discount Link and have items in their cart, even if you deactivate the Discount Code using the instructions listed above, the customer will still receive the discounted price for those products added to their cart prior to the Discount Link being deactivated.
If you want to remove this possibility you need to clear your customers' carts by setting the option Number of Days to Save Shopping Cart Contents to 0 (zero) under Settings >> Site Wide Settings >> System Options tab.
Steps to Clear Customer Carts on Your Site: