Amazon glossary

What are negative keywords?

Negative keywords — Search terms you block from your ads.

By AIAdKing Editorial Team · Reviewed September 3, 2026

Negative keywords — Search terms you block from your ads: Amazon negative keywords are search terms you block so your ads stop showing for them. Adding a search term that gets clicks but no sales as a negative keyword stops it wasting budget — one of the fastest ways to lower ACoS.

In depth

Sponsored Products ads — especially automatic and broad-match campaigns — can match a wide range of shopper searches, and some of those searches will never convert for your product yet keep spending your budget. Harvesting them as negative keywords (negative exact for one term, negative phrase for a whole family of terms) cuts the wasted spend without touching the searches that do convert, which is why it is usually the first lever in any serious ACoS clean-up. The profitability effect is direct: every dollar a dead search term stops burning drops straight out of the ACoS numerator while sales stay untouched. The hard part is doing it continuously across thousands of terms — our negative keywords guide walks the manual workflow step by step, and PPC automation exists in large part because this particular job never ends.

Worked example

Your automatic campaign for a stainless-steel water bottle matches the search term "plastic sipper for kids". Over a month it collects 85 clicks at a $0.42 average CPC — $35.70 spent — and zero orders. Ten terms like it and you have burned $350+ for nothing, silently inflating ACoS. Adding "plastic" as a negative phrase blocks the whole family of mismatched searches at once; adding the exact term as negative exact blocks just that one. If the campaign was doing $2,000 of monthly ad sales on $600 spend (30% ACoS), removing $350 of dead spend drops ACoS to 12.5% on the same sales.

When to use it

Run a harvest weekly on automatic and broad campaigns (they generate the most junk matches) and after any unexplained spend spike. Use negative exact to kill a single proven loser, and negative phrase only when every search containing that word is genuinely irrelevant to your product.

Common mistakes

Negating too early — three clicks without an order is normal variance, not a verdict; wait for enough clicks (10–20, depending on price) before blocking a term.
Using negative phrase when you meant negative exact — negating the phrase "bottle kids" also blocks "steel bottle kids school", which might have converted.
Never revisiting the list — a term that converted poorly at launch can become a winner once your reviews and price improve; audit your negatives quarterly.

How AIAdKing handles Negative keywords

AIAdKing harvests negative keywords continuously: it flags search terms with enough clicks and no orders, blocks them with a logged reason, and never negates a term that is also converting — so you cut waste safely.

Negative keywords — quick answers