See what one order is really worth on each channel (Lesson 4.1), then find the ad targets each channel can afford (Lesson 4.3). It starts with the Northbound Coffee worked example — the fees are illustrative, so replace them with your platforms' current rates.
1. Your product
One product, priced the same everywhere. Target profit is what you want left per order after advertising.
2. Your channels
Per-order costs for each place you sell. Percentages apply to the order value (price plus any shipping you charge).
3. Comparison
Break-even is the most you can spend on ads per sale before every ad-driven order loses money.
4. Your channel summary
The one-paragraph version for your plan — and for the capstone in Module 7.
How it's calculated
Order value = price + shipping charged to the customer
Contribution margin = order value − product cost − (fee % × order value) − fixed fee − fulfillment − shipping you pay − (creator % × order value) − (returns % × order value)
Break-even ACoS = contribution margin ÷ order value · Break-even ROAS = order value ÷ contribution margin
Target ACoS = (contribution margin − target profit) ÷ order value · Target ROAS = 1 ÷ target ACoS
Profit per ad-driven order = contribution margin − (order value ÷ your ROAS)
Returns are modelled as an allowance: the share of order value you expect to lose to refunds and write-offs. Fee structures vary by platform, category, and country — check each platform's current fee pages.