---
title: "Post-purchase upsell: definition and formula"
description: "An offer shown after payment and before the confirmation page, added to the order in one click. It cannot cost the original sale."
url: https://offersuite.io/glossary/post-purchase-upsell
updated: 2026-10-13
---

# Post-purchase upsell

An offer shown after payment and before the confirmation page, added to the order in one click. It cannot cost the original sale.

## In plain words

A post-purchase upsell is an offer made after the customer has paid and before they reach the confirmation page. They can add it with one click, without entering payment details again, and it joins the order they just placed.

Its appeal is that it risks nothing. The first sale is already made, so an upsell that is declined costs nothing. One that is accepted ships with the original order and pays only for its own product, an extra pick and its fees.

## Formula

- Margin added = upsell price − its unit cost − extra pick − costs charged as a share of its price
- Profit per order shown = margin added × the share of buyers who accept

## Worked example

After buying one $40.00 bag, the customer is offered a second at 25% off. If they accept, the order brings in $70.00 and the engine puts its margin at $30.79, up from $15.36.

The discounted second bag added $15.43, more than the first bag earned at full price, because the label and the base fee were already paid.

### 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.

## A post-purchase upsell is not part of the original sale

The customer agreed to it separately, after paying. In a report it should show as its own line, added to the order later. Folding it into the first sale makes the original offer look better than it was, and hides how often the upsell is taken.

## Using it

Offer something that needs no thought: more of what they just bought, or its obvious companion, at a clear saving. Measure the acceptance rate and the margin added per order shown. Because it ships with the first order, check that it does not delay the parcel or split it.

## In Offer Suite

In Offer Suite a paid line that an order edit adds after the sale, such as a post-purchase upsell, is stored as its own costed line of the order. A line that an accepted Offer Suite upsell sold is reported in the upsell offer's own figures, apart from the offer that won the order.

Source: Offer Suite's money definitions, checked against real Shopify orders.

## Related

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- [Glossary **Add-on: definition, formula and example** 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.](https://offersuite.io/glossary/add-on)
- [Glossary **Gross revenue: definition, formula and example** An order's revenue as Offer Suite books it: line prices after discounts plus shipping charged, tax excluded, frozen at the sale as placed.](https://offersuite.io/glossary/gross-revenue)
- [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)
- [Glossary **Average order value (AOV): definition and formula** Total order revenue divided by the number of orders. Useful for spotting a trend, misleading for setting thresholds because it hides the shape of your orders.](https://offersuite.io/glossary/average-order-value)