A euro of revenue is not worth the same on every product. Reporting campaigns by gross profit, and not just revenue, shows what really remains after product costs. It changes budget decisions and shows where a good ROAS hides a poor business.
The essentials in a definition
Reporting margin instead of revenue means assessing campaigns by the gross profit they generate (revenue less product cost, returns, commissions and shipping) rather than sales value. It avoids decisions that increase volume and decrease profit. It requires sending the platforms a coherent conversion value, through conversions with value and value-based bidding.
Revenue is not profit
A campaign with high ROAS may sell low-margin products, while another with lower ROAS sells very profitable ones. Looking only at revenue favours the first, when the second brings more money to the company.
In shops with many categories and different cost prices, this difference can be large.
How to calculate gross profit by campaign
Attach to each product its cost (purchase or production) and add whatever is relevant: shipping, commissions, payment fees. Subtract from the selling price to obtain margin. Multiply by the sales attributed to the campaign.
If you do not have exact cost, start with an average margin per category. A reasonable approximation is better than ignoring the subject.
From ROAS to profit after ads
- Gather each product’s cost
- Calculate gross margin per product
- Send margin to platforms or segment the feed
- Report profit after ad costs
Bringing margin to the platforms
Many platforms let you send a custom conversion value. If you send margin instead of revenue, the algorithm looks for profit. Or use margin labels in the feed to segment and bid differently.
Keep consistency and document the method, so that anyone on the team can understand and review it.
Selling more is not the same as earning more.
Reporting clearly
Present revenue, margin, ad cost and profit after ads. Include returns and discounts where possible. Compare by campaign and by product category.
Show the evolution over time. The aim is not a perfect number but reliable guidance on where to invest.
Decision table
| Metric | Simple calculation | When to use |
|---|---|---|
| ROAS | Revenue ÷ spend | Quick reference, ignores margin |
| Gross margin | Revenue − product cost | Choosing products and categories |
| Contribution | Margin − spend − returns and shipping | Budget decisions |
| Profit per customer | Contribution over time | Acquisition and repurchase |
Common mistakes to avoid
- Ignoring returns. Revenue with many returns is not margin.
- Using average margin. Different products have very different margins.
- Changing the formula in each report. Define the rule and keep it.
How to measure the result
Each month, compare the contribution estimated by campaigns with the real margin from the financial system. If they diverge, adjust the category margins.
Limits and exceptions
Reporting margin requires cost and return data that are not always available or stable, and margins can vary by supplier, season and volume. Category estimates are approximations. Use them transparently, update them when costs change and do not present them as exact. If there are no reliable data, start with conservative estimated margins and improve recording over time.
Illustrative example
Illustrative example: an electronics shop sees ROAS fall after excluding low-margin products, but total contribution rises. It starts reporting contribution per campaign and sending the platform a conversion value based on margin by category. Management better understands the result because the report shows profit, not just revenue.
In practice: checkpoints
Check that product costs are updated at least monthly, that returns are subtracted and that finance agrees with the margin definition.
Frequently asked questions
Do I need exact margin per product?
It helps, but an average margin per category already improves decisions.
Does this change bidding?
It can, if you send margin to the algorithm as the conversion value.
What about returns?
Including them gives a more realistic view of profit. Start with averages.
How do I calculate margin per product?
Selling price excluding VAT, less product cost, commissions and variable costs, by category or product.
Should I report ROAS to management?
Show it alongside margin and contribution, to avoid misleading readings.
Reporting margin instead of revenue shows campaigns’ real profit and avoids growing volume at the expense of profitability.
Sources and recommended reading
- Google Ads API: conversion management
- Google Ads Help: Smart Bidding
- Analytics Help: GA4 recommended events
Last editorial review: October 2026. Informational content; always confirm current conditions in the official sources before deciding.