Open a Search Term Report and it's common to find ad spend leaking into search terms that never lead to sales. Negative keywords are the fix. Here's the concept and how to actually manage them.
What is a negative keyword?
It's an instruction telling Amazon not to show your ad for a specific search term. Separate from Targeting (the keywords you're aiming for), it's a list of terms you're explicitly excluding — "never show my ad for this search." Auto campaigns and Broad Match keywords in particular tend to match broadly, so irrelevant search terms show up often, which makes negative management essential.
Negative Exact vs. Negative Phrase
Negative Exact: blocks your ad only for searches that exactly match the term you add. Adding "B brand similar product" as Negative Exact blocks your ad only when someone searches that exact phrase.
Negative Phrase: blocks any search containing that phrase. Adding "free" as Negative Phrase blocks your ad for "free shipping Product A," "free sample Product A," and anything else containing that word. Since it blocks much more broadly, use it carefully — cast too wide a net and you can block search terms that would have actually converted.
Which search terms should become negatives?
Open your Search Term Report and look for these patterns:
High clicks, zero orders: especially once a search term has accumulated 10-20+ clicks with no orders, that's a strong signal of low relevance.
Search terms clearly unrelated to your product: if you sell Product A and terms like "B brand authentic" or "used Product A" show up, those searchers likely aren't your target customer.
Search terms already well-covered by another campaign or keyword: to avoid multiple campaigns competing against each other for the same search term (cannibalization), it's common to negative that term out of the lower-priority campaign.
Cadence and workflow
Review your Search Term Report at least weekly, screen for candidates using the criteria above, and start narrow with Negative Exact before expanding to Negative Phrase once a pattern is clear. Rather than negativing a large batch of keywords all at once, it's safer to work through terms gradually as data accumulates.
Key takeaway
Negative keywords stop ad spend from leaking into irrelevant search terms. Use Negative Exact for narrow, precise blocking and Negative Phrase for broader blocking — carefully. Reviewing your Search Term Report regularly and starting with "clicks but no orders" terms is the basic workflow.