To create a site-wide discount:
- Go to Marketing > Coupon/Discounts in your Admin Area.
- Click Add.
- Enter a name for your discount in the Discount Name field. You do not need to select Coupon and add a Coupon Code if you want the discount to be automatically applied.
- Select Percent Off Entire Order from the Discount Type menu.
- Fill in Discount Value with the discount amount (for example, "10", if you want to offer a site-wide 10% discount).
- Click Save.
You can also make that discount applicable only for a given date range (a three-day special, etc.), as well as many other options, all noted within the detail edit page for the coupon/discount.
The discount will be displayed and applied on the cart page.