Conversions with cart data

Conversions with cart data is a Google Ads extension to purchase tracking that sends each order’s item IDs, quantities and prices, so Google Ads can report gross profit.

By Berend Vrakking, founder of Product Metrics. Updated 13 November 2026.

Cart data example

One order after a click on a Shopping ad for Trail Runner 2
Item sold	Revenue minus COGS	Gross profit
Trail Runner 2 (the advertised product)	€100.00 − €45.00	Lead: €55.00
2 × Everyday Sock (another product)	€20.00 − €6.00	Cross-sell: €14.00
Order	€120.00 − €51.00	Total: €69.00

Google Ads reports €120.00 revenue and €69.00 gross profit for the click, split into the advertised product and the cross-sell. An item without a COGS value is left out of gross profit. Illustrative data.

Put it into practice

Calculate it: POAS calculatorCompare profit and revenue on the same ad spend.
Read the guide: POAS vs ROASCompare profit and revenue as the return to bid on.

Cart data: one product and the whole account

Cart data works per item: the purchase tag sends each item’s ID, price and quantity, and the ID must match the id in a linked Merchant Center account. Google Ads adds cost_of_goods_sold from the feed and reports gross profit per product and per campaign.

For the account, cart data changes reports, not bidding. Google Ads has COGS but no POAS bid strategy. Maximise conversion value, with or without a target ROAS, steers on whatever value you send, so sending profit as the conversion value lets it act on profit.

Full Signal Tracking sends profit to Google Ads and Meta as its own conversion action next to revenue, from an endpoint on your own domain. Conversion value divided by cost then reads as a POAS.

Cart data: common mistake

Adding cost_of_goods_sold to the feed and expecting Google Ads to bid on profit. COGS fills the gross profit columns; bidding still works on the conversion value you send.

Cart data: questions

How do you set up COGS tracking for Google Shopping?

Add cost_of_goods_sold to each product in Merchant Center, through the feed, the API or a supplemental feed, and add cart data to your purchase tag. Gross profit reporting needs both. Merchant Center uses COGS for reporting only, so an average cost is fine.

How do you send profit instead of revenue as the conversion value?

Calculate each order’s profit in your own system and send it as the value of a purchase conversion action. Cart data does not do this: it reports gross profit but leaves the value as sent.

Net profit or gross profit as the Google Ads conversion value?

Use profit you can work out per order: gross profit, or gross profit minus variable costs such as shipping and payment fees. Net profit carries fixed costs that belong to no single order. Leave ad spend out; bidding already divides value by cost.

Should shipping costs be included in Google Ads conversion value?

For a profit value, subtract the shipping you pay. Google Ads Help sets no rule for the conversion value itself; in cart data, the item price excludes tax, shipping and order-level discounts.

How do you bid on profit without showing Google your margins?

Send profit per order as the conversion value and leave cost_of_goods_sold out of the feed. Google then sees each order’s profit, but not each product’s cost.

Sources

Keep reading

POASThe return you read when profit is the conversion value.
Cost of goods soldThe cost Merchant Center holds for each product.
Conversion valueThe number bidding steers on, which cart data leaves as sent.
Primary conversion actionChoose whether revenue or profit is the action bidding uses.
POAS conversion value biddingPass profit to Google Ads and compose the conversion value.
COGS and margin for Google ShoppingConnect product costs and margin to Shopping end to end.