How to cut Amazon ACoS by half in 90 days
The campaign restructure that takes most Seller Central accounts from 40% ACoS to under 20%, with the exact steps in order.
- Most high-ACoS accounts have one problem: auto and broad campaigns running without negative keyword sculpting.
- Restructuring into single-keyword ad groups gives you bid control you cannot get any other way.
- Harvest search terms weekly, negate aggressively, and move winners into exact match.
- Expect 30–55% ACoS reduction within eight to twelve weeks with sales holding or growing.
Why your ACoS is high
Nearly every account we audit has the same structure: a few auto campaigns, a few broad campaigns, and one giant ad group with forty keywords sharing a bid.
That structure cannot be optimised. When forty keywords share one bid, you are overpaying for the good ones and underpaying for the great ones, and you have no way to tell them apart.
Step one: turn auto campaigns into research
Do not kill your auto campaigns. Repurpose them. An auto campaign at a low bid is the cheapest keyword research tool Amazon offers.
Set the bid low, let it run, and mine the search term report weekly. Anything converting goes into an exact match campaign. Anything spending without converting gets negated immediately.
Step two: single-keyword ad groups
Move every proven keyword into its own ad group with its own bid. This is more work to set up and vastly easier to optimise.
Now when a keyword converts at 15% ACoS you can raise its bid without raising the bid on the keyword converting at 60%. That granularity is the entire game.
Step three: negate ruthlessly
Weekly, open the search term report, sort by spend descending, and look at everything with clicks but no conversions.
Anything with more than ten clicks and zero sales gets negated at exact match. Anything clearly irrelevant gets negated at phrase match. This single habit typically cuts 20% of wasted spend in the first month.
Step four: placement and dayparting
Check the placement report. Top of search usually converts best and costs most — if your ACoS there is good, increase the placement modifier and let Amazon buy more of it.
Then check performance by hour if your volume supports it. Most B2C accounts have dead hours overnight where spend continues and conversions do not.
What to expect
Weeks one to two: restructure, negate the obvious waste. ACoS often drops immediately just from stopping the bleeding.
Weeks three to six: exact match campaigns mature, bid data accumulates, you start raising bids on winners.
Weeks eight to twelve: ACoS stabilises 30–55% below where it started, with sales flat or up. One home goods client went from 41% to 18% while revenue nearly tripled.
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Related questions
What is a good ACoS?
It depends entirely on your margin. If you make 40% gross margin, breakeven ACoS is 40% and you want to be meaningfully below it. Chasing a 10% ACoS on a low-margin product usually means you have throttled your own volume.
Should I use automatic or manual campaigns?
Both. Auto for discovery at a low bid, manual exact for the keywords that prove themselves. Auto alone is expensive; manual alone means you never find new terms.
How long before I see results?
Wasted spend cuts show within two weeks. Structural ACoS improvement takes eight to twelve weeks because exact match campaigns need conversion data before you can bid confidently.
