--- title: "Add-on: definition, formula and example" description: "A second product offered alongside the main one, to go in the same order. It pays only its own cost and a pick, so most of its price is margin." url: https://offersuite.io/glossary/add-on updated: 2026-10-13 --- # Add-on A second product offered alongside the main one, to go in the same order. It pays only its own cost and a pick, so most of its price is margin. ## In plain words An add-on is an extra product offered with the main purchase: a mug with the coffee, a case with the phone. It is shown in the buy box or the cart, before the customer pays, and ships in the same parcel. It is some of the cheapest margin a store can find. The order already pays for its label, its base fee and its box. The add-on brings its own unit cost, one more pick and the fees charged on its price. Everything else it sells for is kept. ## Formula - Margin added = add-on price − its unit cost − extra pick − costs charged as a share of its price ## Worked example A mug offered at $9.00 with the $40.00 bag takes the order to $49.00. The engine puts the order's margin at $19.45, up from $15.36. The mug added $4.09 on a $9.00 sale. Sold on its own, with its own label, the same mug would lose money. ### The example order A $40.00 bag of coffee, shipped free, every cost counted Revenue $40.00 to contribution margin $15.36 (38.4%) Revenue $40.00 Cost of goods −$12.00 Pick and pack −$1.18 Packaging −$0.50 Shipping label −$7.50 Card fee per order −$0.30 Refunds −$2.00 Card processing −$1.16 Contribution margin $15.36 2 declared kinds cost nothing on this option Computed by the margin engine in Offer Suite's own code, in whole cents, from a $40.00 bag of coffee with a $12.00 unit cost. ## An add-on is not a gift The customer pays for an add-on, and it has revenue. A gift has none. They sit in the same box and cost the same to pick, which is why they get confused in reports. An add-on raises the order's margin and a gift lowers it. ## Using it Offer add-ons that are light, small and already stocked with the main product, so they add a pick and nothing else. Check that the add-on does not push the parcel over a weight or box step. And measure how many buyers take it: an add-on taken by one buyer in five still moves profit per visitor. ## In Offer Suite In Offer Suite an add-on is a line of the option with its own role, priced and costed with the rest of the order, so the forecast shows what the option keeps with it. Source: Offer Suite's margin engine. ## Related - [Glossary **Glossary of offer economics** The terms behind offer profit, defined plainly with their formulas and a worked number: contribution margin, profit per visitor, break-even lift and more.](https://offersuite.io/glossary) - [Calculator **Offer option calculator: profit per visitor** Compare up to three offer options on profit per visitor, margin per order times conversion, and see the conversion lift each one needs to match the best.](https://offersuite.io/calculators/offer-option-profit-per-visitor) - [Calculator **Gift with purchase profit calculator** What a free gift costs per order, after its unit cost, its extra pick and its handling, and how much conversion it has to add to pay for itself.](https://offersuite.io/calculators/gift-with-purchase-profit) - [Glossary **Post-purchase upsell: definition and formula** An offer shown after payment and before the confirmation page, added to the order in one click. It cannot cost the original sale.](https://offersuite.io/glossary/post-purchase-upsell) - [Glossary **Gift with purchase: definition, formula and example** A free item added to an order to win the sale. It leaves the price alone and adds a unit cost, a pick and sometimes a heavier parcel.](https://offersuite.io/glossary/gift-with-purchase) - [Glossary **Unit economics: definition, formula and example** The revenue and costs of one unit of sale: an order, a customer or a subscriber. For an offer, the unit that matters is the order, then the customer.](https://offersuite.io/glossary/unit-economics)