ACoSAdvertising Cost of Sale
ACoS is the percentage of attributed ad sales spent on advertising. A lower ACoS means your ads are generating revenue more efficiently.
What is ACoS?
ACoS — Advertising Cost of Sale — is calculated by dividing your total ad spend by your total attributed sales, then multiplying by 100. If you spend $50 on ads and generate $200 in attributed sales, your ACoS is 25%. It is the primary efficiency metric for Amazon PPC campaigns and appears directly inside Seller Central's advertising reports.
ACoS only counts sales that Amazon directly credits to a click on your ad (within a 7-day attribution window by default). A customer who sees your ad, leaves, and comes back organically three weeks later will not count toward ACoS — but they would count toward TACoS. This attribution window distinction matters enormously when evaluating campaign performance.
Break-even ACoS is the percentage equal to your net margin after COGS and fulfillment fees. If your margin is 35%, any ACoS below 35% is technically profitable. Many experienced sellers set a target ACoS 10–15 percentage points below break-even to leave room for other operating costs.
Why it matters for sellers
ACoS is the single number most sellers check first when opening their advertising dashboard. It tells you, at a glance, whether your campaigns are profitable or burning cash. A high ACoS (above your break-even) means you're paying more to acquire a sale than the sale is worth — a pattern that destroys margins at scale.
Beyond profitability, tracking ACoS over time reveals whether your listing quality is improving. If your bids stay constant but ACoS drops, your conversion rate has improved — the listing is doing more of the selling work so each click is worth more. Conversely, a rising ACoS with flat bids is a signal to audit your listing, pricing, or review count.
How to use ACoS
Start by calculating your break-even ACoS: (Revenue − COGS − FBA fees − other costs) ÷ Revenue × 100. This is your ceiling. Set your target ACoS 5–10 points below that ceiling to leave a margin buffer.
Run separate campaigns for broad, phrase, and exact match keywords. Broad match will show a high ACoS but harvest converting search terms. Move those terms to exact match campaigns at tighter bids to lower ACoS. Add negative keywords aggressively — irrelevant clicks are the fastest way to inflate ACoS without any compensating revenue. Review campaigns weekly during launch and monthly once stable.
Real-world example
You sell a yoga mat at $45. COGS + FBA fees = $18. Margin = $27 (60%). Break-even ACoS = 60%. You target 35% ACoS for a healthy profit. In month one you run at 52% ACoS — acceptable during launch. By month three, after adding 40 negative keywords and moving top converters to exact match, ACoS drops to 28%. You're now comfortably profitable and organic rank has improved enough that TACoS is 12%.
AI product photography
Cut your photography costs by 94% with AI
Sellable generates studio-quality product photos, UGC-style video ads, and A+ Content visuals — all from a single product image. Used by Amazon and Shopify sellers to eliminate $3,000+ monthly studio costs and lift conversion rates.
Frequently asked questions about ACoS
What is a good ACoS on Amazon?
A 'good' ACoS depends entirely on your margins. Calculate your break-even ACoS (net margin %) and target something 5–15 points below it. For most consumer goods sellers, 15–30% is a healthy target range, but a supplement brand with 70% margins can afford 50% ACoS and still profit.
What is the difference between ACoS and TACoS?
ACoS measures ad spend against ad-attributed sales only. TACoS (Total Advertising Cost of Sale) measures ad spend against all revenue — organic + paid. TACoS is a better long-term health metric because it shows whether your PPC investment is building organic momentum or just paying for every single sale.
Why is my ACoS so high?
High ACoS usually has one of three causes: irrelevant traffic (fix with negative keywords and match type tightening), low listing conversion rate (fix with better images, pricing, and reviews), or overly aggressive bids (reduce bids on non-converting terms). Run a search term report to find where spend is going.
Does a high ACoS during launch hurt my account?
No — Amazon doesn't penalise accounts for high ACoS. A high ACoS during launch is expected and often strategically correct: you're paying to generate sales velocity and keyword ranking. What matters is managing total ad spend against your cash flow budget, not the ACoS number itself.