I have advertisements in which we offer coupons for some value off from the purchase price.
we use simple cash registers and so enter daily sales as a customer "Register 1"
with service item "breakfast" used to record that registers breakfast sales. This is a TAX able entry and so I must enter the total minus sales tax. in this way the computing of sales tax can go on correctly (that's for another post).
After much reading of community posts and making a few experiments I have a method that appears to work.
1) create an expense account "60000 · Advertising and Promotion:Coupons" Tax-Line Mapping "Deductions:Advertising"
2) create a non-inventory part "coupon" set the tax code to Nontax, and the Account to your just created expense account "60000 · Advertising and Promotion:Coupons"
3) make sales receipt and add a line with item "coupon" QTY - the number of coupons, RATE the amount of the coupon as a negative number
this has the flexibility for multiple value coupons to be entered simply by changing the rate OR by creating different items if you want to track that way.
I have not figured out how to get the QTY out of the Sales Receipts for reporting.