The calculation that flipped the "best" channel into the worst

The calculation that flipped the "best" channel into the worst

An ecommerce brand crowned Google Shopping their top channel: highest revenue, clear winner. But the bank account disagreed with the dashboard. Revenue isn't profit.

The true-ROI playbook:
— Pull revenue by channel from GA4 for the period
— Layer ad spend per channel from the ad platforms
— Subtract cost of goods and shipping per order, not just ad cost
— Calculate contribution margin per channel, not revenue
— Re-rank channels by margin dollars, not top-line

Shopping drove the most revenue but ran at a 2% margin after discount-driven returns. Email, ranked fourth by revenue, ran at 41% margin and quietly out-earned it in actual profit.

They shifted budget toward email and margin grew 9% with flat revenue.

Lesson: revenue picks the loudest channel. Margin picks the one that pays your salary. Rank by the second.