Which coupon saves more: 20% off the whole cart or 30% off one item in it?

Compare the money saved, not the rate

The rate alone tells you little, because each coupon applies to a different amount. 30% is bigger than 20%, but it is taken from 200, while 20% is taken from 500.

1. Open the Discount calculator and enter the cart total, 500, with 20. The saving is 100.
2. Enter the item's price alone, 200, with 30. The saving is 60.
3. The coupon with the bigger saving wins for this cart: here the cart coupon, by 40.

When the item coupon wins

The item coupon comes out ahead when the item is most of the cart. The break-even point: item price = cart total × 20 ÷ 30, which is two thirds of the cart. In a 500 cart that is an item at about 333.33, where 30% off saves 100, exactly like the cart coupon.

Before you apply a coupon

• Read the terms: a cart coupon may exclude certain products or sale items, so it only applies to part of the cart. Enter the amount it really covers.
• Shipping is usually outside the discount. Leave it out of the cart total.
• If the store lets you use both coupons, each applies to a different part; work each out on its own and add the savings.

For sellers: which one should you launch?

The same sums tell you what each coupon costs you. 20% off the cart costs 100 on a 500 order; 30% off a 200 item costs 60. The item coupon is cheaper and more focused: good when you want to move one product, or when that product's margin is high enough to carry a bigger rate. A cart coupon encourages bigger orders, but it also cuts into products whose margin may be thin.

If you run a big rate on a single product, say so clearly in the ad, so nobody reads it as 30% off everything and feels let down at checkout.