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.