Amazon negative keywords: when to add them and how much data you need

Negative keywords tell Amazon not to show your Sponsored Products ads for certain searches. Use negative exact to block one specific search term and negative phrase to block every search containing a phrase. Add them right away for searches that clearly aren’t your product, and for relevant-looking searches, wait until the term has had enough clicks to judge against your normal conversion rate.

Negatives are the cheapest profit lever in Amazon ads. Every dollar they save goes straight back to you. But they cut both ways: negate too much, too early, and you shut off searches that would have sold.

Negative exact vs. negative phrase: what’s the difference?

Start with negative exact. It’s precise, and you can see exactly what you blocked. Use negative phrase when you see the same unwanted word showing up again and again across many search terms, like a material you don’t sell or a use your product doesn’t fit.

There’s also negative product targeting, which blocks your ads from showing on specific product pages (by ASIN) or, in some cases, specific brands. It’s useful in auto and product targeting campaigns when you see clicks from product pages that never convert. Sponsored Products doesn’t offer a negative broad match; as of September 2026, check the Ads console help under “negative keywords” for the current options and limits.

Campaign level or ad group level?

You can add negatives to a whole campaign or to a single ad group. Use campaign level when a search is wrong for every product in the campaign. Use ad group level when it’s wrong for one product but right for another, like a “large” search that fits your large board but not your small one.

When should you add a negative keyword?

There are two kinds of candidates, and they need different rules.

• Irrelevant searches. The shopper was looking for something you don’t sell. A cutting board brand paying for “bamboo plates” or “cutting board oil.” You don’t need data to know these won’t convert well. Negate on sight.
• Relevant searches that aren’t converting. The search looks right, but the orders aren’t coming. These need patience, because a few clicks with no sale is normal even for great keywords.

The second group is where most sellers go wrong, usually by negating too fast.

How much spend before you judge a search term?

The honest answer is: it depends on your conversion rate. Here’s the reasoning.

Say your product usually converts at 10%, meaning about 1 order per 10 ad clicks. A search term that gets 5 clicks and no orders tells you almost nothing. Even a perfectly good term will often go 5 clicks without a sale at a 10% conversion rate.

As clicks add up, a zero-order result gets harder to explain as bad luck. At a 10% conversion rate, the chance of a good term getting zero orders in 20 clicks is roughly 1 in 8. At 30 clicks, it’s under 1 in 20. That’s why a common rule of thumb is to wait for about two to three times the clicks you normally need for one order before calling a relevant term a dud.

If your conversion rate is lower, say 5%, you need about 20 clicks per order, so wait for 40–60 clicks. If it’s higher, you can decide sooner. Find your own rate by dividing orders by clicks across a month of ad data.

Before negating a relevant term, consider lowering its bid instead. A search that converts, just too expensively, is a bidding problem, not a negative keyword problem.

How do you harvest an auto campaign?

Auto campaigns let Amazon choose which searches and product pages to show your ad on. They’re great for discovery and wasteful if you never prune them. Harvesting means moving the good searches out and blocking the bad ones.

Step 4 is the one people skip. Without it, both campaigns can compete for the same search, your data splits in two, and it gets harder to tell what’s working. The report itself is explained in how to read the Amazon search term report.

What are the most common negative keyword mistakes?

• Negating your own brand name by accident. A broad negative phrase like your brand name in the wrong campaign can stop your ads from showing when people search for you. If you negate brand terms in non-branded campaigns, make sure a separate branded campaign covers them.
• Negating too early. Five clicks and no sale is normal. Use your conversion rate to set a threshold and stick to it.
• Using negative phrase with a single common word. Negating “set” or “large” as a phrase can block searches you want. Check what else contains that word before you add it.
• Negating a term everywhere when it’s only wrong for one product. Use ad group level negatives when products differ.
• Negating converting terms because ACoS is high. Lower the bid first. Negatives are for searches that won’t sell, not searches that sell at the wrong price.
• Never reviewing old negatives. Products, listings and prices change. A term that didn’t convert last year may now. Skim your negative list a couple of times a year.

How do you know negatives are working?

Watch three things over the following few weeks: spend in the campaign should drop or hold steady, orders should hold steady, and ACoS should come down. If orders drop along with spend, you probably blocked something that was selling. Undo the most recent broad negatives first.

If you haven’t worked out what ACoS you’re aiming for, start with ACoS vs. TACoS. Your break-even ACoS is what makes every negative keyword decision easier.

Negative keywords aren’t exciting. But a steady, patient habit of adding a few each week, based on real data rather than gut feel, is one of the most reliable ways to make the same ad budget go further.