How to Use Amazon Negative Keywords (With the Math for When to Add One)

A negative keyword tells Amazon which searches your ad should never serve, no matter what your targeting would otherwise match. That's the whole feature. What makes it worth your attention is the money. One search term on my own account racked up 336 clicks without a single sale. At even $0.75 a click, that's $252 spent proving a term doesn't convert, and the ads would have happily kept spending it. A negative keyword is how you stop paying for a lesson you've already learned.

The two match types, precisely

Amazon gives you two kinds of negative keyword, and the difference decides how much traffic each one blocks.

Negative exact blocks a search only when it matches your negative keyword as the whole search, including close variants like plurals. Negating "leather wallet" as exact blocks "leather wallet" and "leather wallets" but still lets "mens leather wallet" through.

Negative phrase blocks any search that contains your phrase anywhere in it, in order. Negating "leather wallet" as phrase also blocks "mens leather wallet," "leather wallet with zipper," and everything else the phrase appears in.

So phrase is the broad hammer and exact is the scalpel. Use exact when a specific search term has proven itself a loser but its neighbors might still convert. Use phrase when a whole family of searches is wrong for your product, you sell dress shoes, "running" as a negative phrase kills every running-shoe search in one line. The caution runs one way. A too-broad phrase negative silently blocks converting traffic, and nothing alerts you when it does. When you're unsure, start with exact and widen deliberately.

Campaign level or ad group level

Negatives can sit on the campaign, where they block every ad group in it, or on a single ad group. The working rule follows from how specific the problem is. A search that's wrong for the entire campaign ("used," "refurbished," a competitor brand you never want to serve) goes on the campaign. A search that's wrong for one ad group's products but right for another's goes on the ad group.

When to negate, with an actual threshold

The search term report is where negatives come from. Sort it by spend, and for each term with meaningful clicks and no orders, the question is whether the term has had a fair chance to convert.

A usable threshold comes from your product's own conversion rate. If your product converts at 10%, a converting search term should produce an order roughly every 10 clicks. By 20 clicks with nothing, the term is underperforming badly. By 30, keep-waiting is costing more than it can teach, at a $0.60 CPC that's $18 spent on one term with nothing back. Negate it as exact and move on. Scale the threshold to your numbers, a 5% conversion rate means giving terms about twice as many clicks before judging.

Two spends per term look small until you multiply by every term in the account. Cutting twenty of those $18 leaks is $360 a month back, which is why this pass is worth running on a schedule and not just when ACoS gets scary.

Negatives and your auto campaigns

If you run the auto-to-manual harvest loop, negatives are half of it. When a converting search term gets promoted from your auto campaign to exact match in a manual campaign, add that same term as a negative exact in the auto. Otherwise both campaigns compete to serve the same search and neither one's data reads clean. The full loop is covered in our auto campaigns guide.

And before negating anything, know your breakeven. A term converting at a 40% ACoS is a problem for a product with a 25% breakeven and completely fine for one at 50%. That math is in what is a good ACoS.

Negative product targeting, the ASIN version

Keywords aren't the only thing you can negate. Sponsored Products also supports negative product targeting, blocking your ad from specific ASINs or brands. It matters most in auto campaigns, where the substitutes and complements groups place you on product pages you didn't choose. If the search term report shows your ad burning clicks on one competitor's detail page without converting (the report shows an ASIN instead of a search phrase for these), negate that ASIN the same way you'd negate a losing search term. Same logic, same threshold math, different target type.

Finding patterns across hundreds of terms

Term-by-term negation catches the big leaks. The subtler waste hides in patterns. The word "case" might appear in forty different no-sale search terms, none individually past your threshold, collectively a real monthly spend. Looking at performance by word rather than by full search term surfaces exactly this, and it's what the N-Grams tool in Merch Jar does, aggregating your search terms into one, two, and three-word fragments with their combined spend and sales. When a fragment shows heavy spend and no orders across many terms, that's a phrase-negative candidate one analysis instead of forty separate judgment calls.

Common negative keyword questions, answered short

Do negative keywords work on auto campaigns?

Yes, and that's their most important home. Autos are where Amazon picks your matches, so negatives are your only lever for shaping what an auto serves.

Negative exact vs negative phrase in one line?

Exact blocks one search (plus close variants like plurals), phrase blocks every search containing your phrase.

Can I remove a negative keyword later?

Yes. Negatives can be archived in campaign manager, and the blocked traffic becomes eligible again. Worth doing when a product's use case broadens and an old negative no longer fits.

Doing this at scale

The pass itself is mechanical. Pull the report, apply your click threshold, negate, repeat weekly. In Merch Jar, the Search Terms view lets you create negative keywords straight from the term's row, and Smart Campaigns can run the whole loop on a schedule, negating search terms that cross your thresholds and promoting the ones that convert, with a dry run mode that previews every change before anything touches your account. 14-day free trial, no credit card.

Wherever you run it, run it on a calendar. The 336-click search term doesn't announce itself. It just keeps billing you until something checks the report.