Bidding on margin for an ecommerce brand on Brightpearl
Treat this as a worked hypothetical rather than a client story. Bidding on profit means sending each order’s margin to Google Ads as the conversion value instead of its revenue, which makes Target ROAS effectively a target return on profit.
The situation
Think of a UK brand selling online, with Brightpearl running orders, stock and costs. Its bestsellers are heavily discounted and expensive to ship, while a smaller range of accessories quietly pays the bills. Google Ads receives the basket total at checkout, so two orders of the same size look identical even if one of them made almost nothing.
Smart Bidding learns from the values you give it. Feed it revenue and it will find revenue, with no interest in whether any was left over after the courier and the card fees.
What does bidding on margin involve?
Google can report gross profit if you send “conversions with cart data” and hold cost of goods sold in Merchant Center. That’s useful, but it’s reporting and doesn’t change what bidding aims at. To bid on margin, the value sent with the conversion has to be the margin itself, which means calculating it somewhere reliable and sending it in a way outsiders can’t read.
What we’d build
A clean purchase conversion first. A Tracking Audit would confirm each order counts once. Profit figures built on double-counted sales would be wrong in a more expensive way.
A margin calculation the finance team has signed off. Using SKU costs from Brightpearl, the integration works out a figure per order: revenue, less product cost, shipping and payment fees, with an agreed allowance for returns. Those rules would live in one place where they can be read and changed.
Margin sent server-side. Putting margin in the website’s data layer would let anyone with developer tools read it. So the order is picked up from Brightpearl after it’s confirmed, the figure is calculated on the server, and the value goes to Google Ads through the Data Manager API.
A decision on how much to reveal. Sharing true margin with an ad platform is a commercial call. Some businesses send a scaled value that keeps the proportions between orders without disclosing the real figure, and the integration would support either.
Adjustments for returns. When Brightpearl records a refund, a conversion adjustment can reduce the value Google Ads holds for that order.
Where does margin bidding usually go wrong?
Cost data is the weak point. A SKU with a missing or out-of-date cost price will look like pure profit, which is how a clearance line ends up as the star of the account. We’d add a check that holds back any order with missing costs and lists it for someone to correct. Returns, shipping and payment fees need the same attention, because each one can turn a healthy-looking order into a loss.
Who changes the bidding?
Whoever runs the account, because campaign and bid management isn’t something we offer. Moving from revenue to margin lowers every conversion value, so any existing Target ROAS stops making sense. That figure would need resetting on the day the new values go live, and we’d plan the date with the in-house team or agency.
How this is scoped
This combines profit bidding with the Brightpearl integration. It would be a fixed-quote project from £2,500, with the final figure resting on what’s involved, and our pricing page lists the rest. Our post on bidding on profit in Google Ads goes through the thinking in more depth.