It is tempting to make a dashboard look richer by assuming a tidy cost of goods, say 40%, and calling the rest profit. It is also a quiet way to mislead the very people who rely on the number most.
The placeholder problem
A fixed margin assumption hides the actual story. Products with thin margins look as healthy as fat ones. A discount that destroys contribution looks harmless. And when someone finally loads real costs, the "profit" line lurches, undermining trust in every other figure on the page.
What honest profit requires
- Real per-unit cost joined from actual product cost data, not a blanket percentage.
- Declared deductions, including tax, refunds, gateway fees, and shipping, are subtracted explicitly.
- A clear label when cost data is missing, so a business without costs sees contribution, never a fake 100% margin.
Until you join a real cost, profit is revenue minus what you can actually prove you spent.
Contribution first
The pragmatic path is to always show contribution, defined as revenue minus ad spend, and reveal the gross-profit and margin columns only once real costs exist. It is less flattering on day one. It is also the difference between a number your CFO can take to the board and one they quietly stop believing.