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GlossaryAdvertisingMetrics

ACoS

Also known as: Advertising Cost of Sale, Advertising Cost of Sales

Advertising Cost of Sale — the percentage of ad-attributed revenue spent on advertising.

ACoS (Advertising Cost of Sale) measures the efficiency of an Amazon PPC campaign as a percentage. The formula is ACoS = Ad Spend / Ad-Attributed Sales × 100. A 25% ACoS means you spent $0.25 to generate $1 of ad-attributed revenue.

ACoS is the default Amazon Ads dashboard metric and the easiest to optimize against, but it has a critical limitation: it only counts revenue Amazon attributes to your ads, ignoring the organic lift advertising creates. Two campaigns with identical ACoS can have very different impacts on overall business profitability. That's why serious sellers track TACoS (Total Advertising Cost of Sale) alongside ACoS.

Target ACoS depends on your unit margin. If a product has 40% margin after fees and COGS, your break-even ACoS is 40%. Anything below that is profitable on the ad-attributed revenue alone. Above that, you're losing money on each ad-attributed sale and need TACoS-level analysis to know whether the campaign is still net positive.

Worked example

A SKU sells for $30 with $12 unit margin. The PPC campaign spent $300 last month and Amazon attributed $1,500 in sales to it. ACoS = 300 / 1500 = 20%. Net contribution: $600 margin from ad sales − $300 spend = $300 profit.

See it in action

TACoS-aware Amazon repricing