Why Is My Amazon ACoS So High?
High ACOS is usually caused by one of three things: irrelevant search terms eating your budget, poor listing conversion rates making every click more expensive, or campaign structure that mixes branded and non-branded targets into one misleading number.
Article summary
High ACOS is usually caused by one of three things: irrelevant search terms eating your budget, poor listing conversion rates making every click more expensive, or campaign structure that mixes branded and non-branded targets into one misleading number.
The longer answer
Short answer: High ACOS is usually caused by one of three things: irrelevant search terms eating your budget, poor listing conversion rates making every click more expensive, or campaign structure that mixes branded and non-branded targets into one misleading number.
What most people get wrong about this
When a brand tells me their ACOS is "too high," my first question is always: too high compared to what?
What I would actually recommend
If you're comparing branded campaign ACOS (which should run 3–12%) against non-branded discovery ACOS (which legitimately runs 30–55% on healthy accounts), the comparison is meaningless. Account-wide ACOS smashes these together into one number that tells you nothing about what's actually happening.
About the author
Irrelevant search terms. This is the \1 cause on every account I audit. Your auto and broad campaigns trigger on search terms that have nothing to do with your product. You pay for clicks that will never convert. On one account I reviewed, 30% of non-branded search terms were completely irrelevant — wasting $70–$80 per day.
Why is my Amazon ACoS suddenly so high?
A sudden ACoS spike is almost always one of three things: a rising CPC auction (competitors bidding you up), your auto and broad campaigns picking up new irrelevant search terms, or a drop in listing conversion rate that makes every click more expensive. Pull your Search Term Report for the last 14 days and sort by spend before touching bids.
What is a good ACoS on Amazon?
There is no single good ACoS. Branded campaigns should run roughly 3-12%, while non-branded discovery legitimately runs 30-55% on healthy accounts. A break-even ACoS depends on your contribution margin. Judging the whole account by one blended number is the most common reason brands think their ACoS is too high when it isn't.
How do I lower my Amazon ACoS without killing sales?
Negate the irrelevant search terms draining spend, fix listing conversion if you're below your category benchmark, and set campaign-type-specific targets instead of one account-wide goal. Cutting bids across the board lowers spend but also kills the campaigns that were actually working.
Does a high ACoS always mean my PPC is failing?
No. A high ACoS on a launch or discovery campaign can be a deliberate investment in ranking and search-term harvesting. ACoS only signals a problem when it's high on campaigns that are supposed to be efficient (branded, exact-match) or when total advertising cost of sale (TACoS) is rising while revenue is flat.