Quick answer
Amazon PPC is Amazon's pay-per-click advertising system — Sponsored Products, Sponsored Brands, and Sponsored Display — where you bid for placement in search results and on product pages. Profitability is decided by one number most sellers never calculate: break-even ACoS, which equals your unit margin before ad spend divided by your selling price. Any ACoS below that figure makes money; above it you are buying sales at a loss, which is sometimes correct during a launch and rarely correct by accident.
Key takeaways
- Break-even ACoS = unit margin before ads ÷ selling price. Without it, every other number is noise.
- Separate campaigns by intent, not by product. Research, performance, and defence have different acceptable ACoS.
- Negative keywords are where the savings are — most wasted spend is search terms you never intended to bid on.
- TACoS tells you whether ads are building the organic rank you are paying for.
The one number to calculate first
Break-even ACoS is the advertising cost of sale at which a campaign contributes exactly zero profit. It equals your per-unit margin before ad spend divided by your selling price. If a $45 product costs $14 to make and $12 in Amazon fees, you keep $19 per unit — a break-even ACoS of about 42%. Spend below that and you profit; spend above it and you are paying for the sale.
Almost every argument about whether an Amazon ad account is 'working' dissolves once this number is on the table. Calculate yours:
Break-even ACoS calculator
Work out the exact ACoS where your ads stop making money — then compare it to what you're actually paying.
Break-even ACoS
42.2%
Spend above this and each sale loses money
Your ACoS
26.7%
ROAS
3.75×
Profit after ad spend
$1,400
Fees = Amazon referral + FBA fulfilment per unit. This models contribution margin only; it excludes fixed overhead, storage, and returns.
Campaign structure: separate by intent
The most common structural error is one campaign per product. It feels tidy and it destroys your ability to make decisions, because a keyword you are researching and a keyword you are defending get judged by the same target. Structure by what the spend is for:
| Campaign type | Purpose | Acceptable ACoS |
|---|---|---|
| Research (broad / auto) | Discover converting search terms | Above break-even — this is tuition |
| Performance (exact) | Harvest proven terms profitably | Well below break-even |
| Brand defence | Own your own branded searches | Very low — cheap, high intent |
| Launch / rank push | Buy velocity to earn organic rank | Deliberately above break-even, time-boxed |
With this structure, a 60% ACoS in a research campaign is a success and a 60% ACoS in a performance campaign is a leak. Without it, both are just '60%'.
The harvest loop
Discover
Run auto and broad campaigns with modest bids. Their job is to generate a search-term report, not to be profitable.
Harvest
Weekly, pull search terms with conversions and move them into an exact-match performance campaign with a deliberate bid.
Negate
In the same pass, add non-converting and irrelevant terms as negatives in the research campaign so you stop paying for them.
Scale
Raise bids only on exact-match terms that convert below break-even ACoS. Everything else holds.
ACoS vs TACoS: measuring the right thing
ACoS measures ad spend against ad-attributed sales. TACoS — total advertising cost of sale — measures ad spend against total sales, including organic. The relationship between them tells you something ACoS alone cannot: whether your advertising is building durable organic rank or just renting sales.
- TACoS falling while revenue grows — advertising is building organic rank. This is the healthy pattern.
- TACoS flat while revenue grows — you are buying growth proportionally. Sustainable, but not compounding.
- TACoS rising while revenue is flat — you are propping up a listing that is not earning organic placement. Investigate the listing, not the bids.
Before you touch bids, fix the listing
Advertising amplifies whatever conversion rate your listing already has. Sending traffic to a listing that converts at 6% when the category average is 12% means paying twice as much per sale for reasons no bid adjustment can fix.
- Main image: does the product read clearly as a thumbnail on a phone?
- Reviews: below roughly 20 reviews, most paid traffic converts poorly regardless of bid.
- Price: is it inside the range shoppers see on the results page, or an outlier they will skip?
- A+ content and bullets: do they answer the top three objections in the first screen?
You cannot bid your way out of a listing problem. You can only pay more for it.
A weekly operating rhythm
- 01Pull the search-term report and harvest converters into exact match.
- 02Add negatives for spend with no conversions above your click threshold.
- 03Adjust bids on exact-match terms — up where ACoS is below break-even, down where it is above.
- 04Check TACoS trend against revenue to see whether organic rank is improving.
- 05Review shop health: out-of-stock risk kills campaigns faster than any bidding mistake.
That loop, run consistently, outperforms almost any bidding tool applied inconsistently. LUSH CODING manages Amazon accounts end to end — campaign structure, weekly optimisation, listing work, and inventory planning.
Frequently asked questions
There is no universal number — it depends entirely on your margin. A good ACoS is one below your break-even ACoS, which equals your unit margin before ad spend divided by your selling price. A 40% ACoS is excellent on a high-margin product and ruinous on a thin one.
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