I want to do a "buy one get one free" coupon on a single product. How would I set up a coupon for that?
Create a coupon that has a Discount Percent of 100%. Set the Discount Application to either Most Expensive or Least Expensive. In the Coupon Application field select the product that the customer will receive for free. In Additional Purchase Required field, select the product that the customer must purchase, and check the Exclude From Discount box.