How to Measure Fashion Email Performance After Returns and Discounts

By Trayan Hristov · Thrivelia · 21 October 2026

A fashion campaign can produce a strong sales report and a much smaller commercial result once discounts, returns and fulfilment costs are visible. The first report answers what the platform credited. The second asks how much value the business retained.

Keep both views, with clear definitions. Connect attributed orders to the order and refund records, allow time for returns to develop, then calculate contribution using the costs the business actually bears.

Separate three different questions

Attributed revenue asks which orders the reporting system credited to a message under its attribution rules. Retained merchandise revenue asks what remains after the relevant discounts, cancellations and refunds. Contribution asks what remains after the agreed variable costs as well.

None of those measures alone establishes incrementality. To estimate what the marketing caused, you need a suitable comparison, such as a well-designed holdout. A campaign can look profitable in attributed reporting while claiming credit for purchases that would have happened anyway.

Our Klaviyo attribution and incrementality guide explains that distinction. This article focuses on making the commercial arithmetic behind a fashion campaign consistent and visible.

Confirm what your platform's revenue field includes

Klaviyo's Shopify data reference documents differences between its revenue calculation and Shopify's, including the treatment of cancelled and refunded orders. Do not assume two dashboards use the same definition because both label a column revenue.

Record the attribution window, order-date rule, currency, treatment of shipping and tax, discount handling and refund treatment. If the order value already includes discounts, do not subtract those discounts again. If refunds have already been removed in the source export, do not remove them a second time.

Use an order identifier to reconcile records and deduplicate orders credited through multiple messages or channels. A sum of overlapping email and SMS views is not automatically a unique set of sales.

A worked example: from merchandise value to contribution

The following figures are illustrative, in one currency, for a hypothetical group of attributed orders. They exclude tax and customer-paid shipping revenue. They are not Thrivelia client results, category benchmarks or an accounting standard.

• Merchandise value before discounts: $1,000.

• Discounts: $100, leaving $900 of merchandise sales before refunds.

• Merchandise refunds and cancellations: $180, leaving $720 retained merchandise revenue.

• Cost of retained goods: $270.

• Returned-item write-offs and lost product value: $20.

• Outbound fulfilment and shipping cost: $60.

• Reverse logistics and return processing: $40.

• Payment costs: $25.

• Variable messaging cost: $15.

The defined variable costs total $430. The resulting contribution is $720 minus $430, or $290. Under these definitions, the contribution margin on retained merchandise revenue is approximately 40.3%.

This is contribution before any costs excluded from the calculation, such as fixed salaries, agency retainers, rent or acquisition costs. It should not be presented as total business profit. Agree the cost definition with the finance owner and use it consistently.

Handle returned stock without double counting

The example charges the cost of goods retained by customers and a separate amount for product value lost on returns. Sellable merchandise recovered into inventory is handled differently from a damaged item that must be written off.

If your data instead starts with cost of goods for every item shipped, apply the appropriate recovery or reversal before adding a separate write-off. Otherwise, the same returned unit can be charged twice. Use the inventory and finance records to establish the actual treatment.

Apply the same care to shipping and payment costs. Customer-paid delivery revenue, refunded delivery charges, retained processing fees and exchange shipping can change the result. Add the relevant fields rather than hiding those differences inside an assumed universal margin.

Why the highest sales figure may not win

Consider a second illustrative campaign with the same $1,000 of pre-discount merchandise value. It uses $200 of discounts and has $80 of merchandise refunds, so retained merchandise revenue is again $720.

Suppose its cost of retained goods is $270, write-offs $10, outbound fulfilment $60, return processing $20, payment costs $25 and variable messaging $15. Its defined variable costs total $400 and contribution is $320.

The first campaign reports $900 of merchandise sales before refunds; the second reports $800. Yet the second retains $30 more contribution under the stated assumptions. The point is the reconciliation, not a claim that deeper discounts improve performance. Different product mix, returns and costs can change the answer.

Give returns a consistent observation window

Recent orders have had less time to be returned. Comparing yesterday's campaign with one sent six weeks ago can make the newer result look artificially strong. Define when an order cohort is mature enough for the question you are asking.

Use a provisional report for immediate operational decisions and a later settled view for commercial evaluation. For each, show the order cohort, reporting cutoff and refund observation period. If extended holiday returns affect the period, record that rather than claiming every order is final at a fixed number of days.

Allocate later refunds back to the originating order cohort when assessing that cohort's economics. A separate refund-date cash view can still be useful, but it answers a different question. Label the two views so a large refund week is not mistaken for the performance of that week's campaigns.

Connect the finding to a decision

High returns concentrated in one fit may point to product guidance or merchandising. High contribution among a small cohort may justify a careful audience-expansion test. High attributed sales with little incremental contribution may call for an offer or contact-policy review.

For an unresolved return, the customer experience also matters. Our returns and exchanges journey guide explains how service state should change the next message. A financial adjustment and an appropriate customer conversation are related pieces of work.

A repeatable campaign review checklist

• State the attribution settings, order population and reporting cutoff.

• Reconcile unique orders before combining channel views.

• Verify whether discounts and refunds are already included in each revenue field.

• Use consistent treatment of retained goods, recovered inventory and write-offs.

• Include the variable costs relevant to the decision and state exclusions.

• Compare cohorts with equivalent time for returns to develop.

• Keep attributed contribution separate from a claim of incremental profit.

Questions teams ask

Should we stop reporting attributed revenue?

Keep it as a diagnostic view. Pair it with retained revenue and a defined contribution calculation. The same campaign can then be assessed for delivery, buying behaviour and commercial value without asking one number to answer every question.

Can we use a single margin percentage for every campaign?

It can be a clearly labelled approximation when detailed costs are unavailable. Review whether product mix, returns, shipping and incentives differ enough to change the decision. Replace the approximation with better data when that becomes possible.

Build the measurement into the programme

Use our fashion and apparel lifecycle guide to connect the findings with fit, adoption and repeat purchase. Thrivelia's fashion email marketing service brings commercial measurement into the planning of journeys and campaigns. Start with one order cohort and reconcile it completely before expanding the report.