There is no universal Amazon ACoS target by revenue tier, account age, or category. A defensible target starts with the seller's current product economics and a documented measurement period. This guide explains the decision inputs BFarm reviews; it does not promise an outcome or disclose an Amazon ranking formula.
Start with break-even ACoS
Break-even ACoS is the product contribution margin available before advertising, expressed as a percentage of revenue. The calculation should use seller-provided price, cost of goods, Amazon fees, fulfillment costs, discounts, returns, and any other agreed variable costs. The source period, formula, exclusions, and as-of date should be recorded because stale costs produce a misleading target.
Illustrative arithmetic: if verified product economics leave 40 percent of revenue before advertising, 40 percent is the advertising break-even point under those assumptions. That example is not a recommended target. The client may require a lower target for profit or may approve a controlled test above break-even for a documented objective.
How account stage changes the questions
Account stage affects uncertainty, not a universal percentage band. A launch usually has less search-term and conversion evidence. A growing catalog may need separate targets by SKU. A mature account may have more history but also more seasonality, branded demand, and inventory constraints. For each stage, document what is known, what remains an assumption, and which decision the data can support.
- Launch: agree a loss limit, inventory constraint, test budget, and review point before spend begins.
- Growth: separate branded and non-branded demand, and review each SKU against its own economics.
- Scale: compare incremental spend with contribution margin and inventory capacity instead of assuming the historical average will hold.
- Mature: review seasonality, placement mix, branded share, and portfolio trade-offs without treating correlation with organic sales as proof of causation.
Use TACoS as context, not a promise
TACoS is advertising spend divided by total sales for the same seller and period. It can show how paid spend relates to total-account revenue, but a change in TACoS does not by itself prove that advertising caused an organic-sales change. Price, inventory, promotions, competition, seasonality, and catalog events may also matter.
Documented decision workflow
- Confirm the client-scoped source reports and their periods.
- Calculate break-even ACoS from current seller-provided costs.
- Write the proposed bid, budget, negative-keyword, placement, or structure change and its reason.
- Agree the measurement window and material assumptions with the client.
- Apply only an approved change, then report what the account evidence shows.
Results and timing remain account-specific. Amazon controls advertising delivery, indexation, and placement; BFarm does not guarantee ACoS, TACoS, sales, or ranking outcomes.
Pair this guide with the weekly PPC review framework, ACoS vs ROAS, and the Advertising Optimization service.