If you run an operating store, you are not here because a campaign looks messy. You are here because the spend-to-order ratio quietly got worse and the search-terms report finally showed you why. Negative keywords are how you take that control back.
Where the controls actually live now
For years the honest answer to "how do I add negatives to Performance Max?" was "you mostly can't." That changed. Full search-terms reporting and campaign-level negative keywords both shipped to Performance Max during the 2025 update wave, according to The Media Image's breakdown of Performance Max transparency and Dataslayer's 2025 Performance Max guide.
Two routes exist today:
- Account-level negatives. In Google Ads, open the Campaigns icon, go to Keywords, pick the Negative keywords tab, and add terms one per line or attach an existing negative keyword list. These apply to every campaign in the account.
- Campaign-level negatives. The same Negative keywords area now lets you scope a list to a single Performance Max campaign, so a term you want blocked in one campaign stays live in another.
One limit matters more than any step-by-step: negatives in Performance Max cover Search and Shopping inventory only, per Google's help doc on negative keywords in Performance Max. That is not a footnote. It is the whole reason the tool works at all for retailers — because for retailers, Performance Max is mostly a feed campaign wearing a cross-channel costume.
Why negatives bite harder than they look
smec, which manages feeds for hundreds of retailers, reports that seventy-four to ninety-seven percent of Performance Max cost goes to feed-based (Shopping-style) ads (smec's 2026 guide to running Shopping alongside Performance Max). So even though negatives skip the Display and video slices, they still govern the large majority of where your budget actually lands.
That is the quiet leverage. A negative keyword list is not nibbling at the edges of a campaign — for most stores it is steering the dominant spend channel.
The expensive problem most guides skip: brand cannibalization
Here is the angle the top-ranking how-to posts almost never cover, and it is where the money is.
Performance Max chases the cheapest conversions it can find. Branded queries — people searching your store name — are the cheapest of all, because the intent is already built. Left unchecked, Performance Max drifts onto those terms, "wins" orders that were coming anyway, and posts a gorgeous ROAS while adding close to zero incremental sales.
Practitioner analyses put the apparent-ROAS inflation from absorbed brand traffic at roughly fifteen to thirty percent, with around eight to fifteen percent of Performance Max budget leaking to brand queries in unprotected accounts (GrowthSpree on branded search cannibalization; ClickTrends on brand cannibalization in Performance Max). smec frames the cost mechanism bluntly: you end up paying "$1.50 for a click that you could have bought for $0.20" (smec).
For brand terms, the cleaner fix is account-level brand exclusions, which Google has offered since 2024 and which cover brand variants and misspellings (AdNabu on excluding brand from Performance Max; Astraloop on 2026 brand exclusions). Negative keywords are your tool for the rest: competitor names, research-intent phrases, wrong-product queries, and anything the search-terms report shows is burning spend without buying orders. The profit math behind all of this is the thread running through our guide to Google Ads economics for Shopify stores.
A worked example: what one negative list is worth
Say you run a store doing 340 orders a month at a $31 average order value, and you spend $2,800 a month on Google through a single Performance Max campaign.
Pull the search-terms report and you find that 18% of spend — about $504 — went to queries containing your brand name or two close competitor names. Those branded clicks were converting at a price far below your non-brand traffic, so they dragged your blended cost-per-order down and made the campaign look sharper than it was.
Now you add brand exclusions plus a short negative list for the two competitor terms. Google is no longer buying the cheap branded clicks, so your reported ROAS drops. That looks like a loss. It is not. Those orders mostly still arrive through organic and direct, because the demand was already yours.
The honest scoreboard is business-level: total orders against total ad spend. If orders hold near 340 while spend on recycled brand traffic disappears, that reclaimed $504 is now free to chase non-brand buyers you did not have before. The campaign's vanity ROAS fell; your actual acquisition economics improved. That gap between reported ROAS and real profit is exactly what we unpack in how cost per acquisition works in Google Ads.
Turning queries into a negative list without guessing
Do not brainstorm negatives from imagination. Read them off the data.
- Open the Performance Max search-terms report. It now shows the actual queries, like a Search or Shopping campaign. Sort by cost.
- Tag each high-cost term as one of: converts well (leave it), converts poorly or not at all (negative candidate), or branded/competitor (exclusion or negative).
- Add the clear waste as negatives, scoped to the campaign if the term might be valuable elsewhere, or account-wide if it is junk everywhere.
- Watch for a recalibration wobble. Smart bidding re-solves after a meaningful change. Google's Target ROAS documentation notes the system needs time to recalibrate after edits — give it one to two conversion cycles before judging the result.
A word of restraint: negatives are a scalpel, not a hedge trimmer. Over-blocking strangles the query variety smart bidding needs to find buyers, and the same documentation warns that over-constraining Performance Max "may limit the amount of traffic your ads may get." Cut the proven waste. Leave the ambiguous terms until the data is clear.
Negatives are a cost-control tool, not a cost-free one
Context matters, because clicks keep getting more expensive. WordStream's 2025 benchmark analysis, reported via Search Engine Land, found roughly eighty-seven percent of industries saw year-over-year cost-per-click increases, averaging about a thirteen percent rise from 2024 to 2025. In retail specifically, LocaliQ's 2026 benchmark data puts the average search cost-per-click at $4.14. Every wasted query costs more this year than last, which is precisely why trimming them pays.
But a negative list does not tell you whether the clicks you keep are profitable. That depends on your margin. The decisional number is break-even ROAS, and it is pure arithmetic:
Break-even ROAS = 1 ÷ contribution margin.
Say a mug sells for $24 and nets $9 after the base cost, shipping share, and processing fees. That is a 37.5% contribution margin, so your break-even is 1 ÷ 0.375 ≈ 2.67x. A query converting below that is losing money no matter how clean it looks — and that is the kind of term a negative list should catch. The structural trade-offs here sit alongside how Amazon and Google Shopping ads compare for a feed-driven store.
Where Victor fits
Reading the search-terms report, reconciling reported conversions against real orders, and spotting brand leak before it compounds is weekly work most operators never get to. Victor, the AI employee from PodVector AI, is a full Google Ads operator that works directly on your live account — he connects to Google Ads, Meta Ads, Shopify, Printify, Printful, Gelato, and Klaviyo, and computes true per-order profit from your real data instead of reported ROAS.
Every write action is approval-gated: Victor surfaces the wasted queries and drafts the negative-keyword and exclusion changes, and nothing executes until you approve it. He is not a dashboard you log into to read charts — he does the diagnosis and proposes the fix. If a store is already spending enough to justify managed help, compare that path in our breakdown of what a Google Shopping ads agency does. You can start with PodVector AI here.
FAQs
Can you add negative keywords to Performance Max at the campaign level?
Yes. Campaign-level negative keywords shipped to Performance Max during the 2025 transparency update, alongside full search-terms reporting (The Media Image). You add them in the same Negative keywords area, scoped to a single campaign. Older guides that say campaign-level negatives are impossible are out of date.
Do negative keywords work on all Performance Max channels?
No. They apply to Search and Shopping inventory only, per Google's help documentation. They do not filter Display, YouTube, Gmail, Discover, or Maps placements. For retailers this covers most of the spend anyway, since smec reports seventy-four to ninety-seven percent of Performance Max cost goes to feed-based ads (smec).
Should I use negative keywords or brand exclusions to stop brand spend?
Use brand exclusions for your own brand. They are account-level, cover variants and misspellings, and have existed since 2024 (AdNabu). Use negative keywords for competitor names and the specific low-value queries your search-terms report exposes. The two tools solve related but different problems.
Will adding negatives lower my ROAS?
Your reported ROAS may fall, especially if you were absorbing cheap branded traffic — practitioners estimate that inflates apparent ROAS by roughly fifteen to thirty percent (ClickTrends). That is the metric correcting, not performance collapsing. Judge the change on total business orders versus total ad spend, not on per-campaign ROAS.
How many negative keywords should I add at once?
Add the clear waste you can see in the data, then stop. Over-blocking restricts the query variety smart bidding needs, and Google warns that over-constraining a campaign can limit traffic (Google Ads Help). After any meaningful edit, give the system one to two conversion cycles to recalibrate before you judge results or cut more.
Do account-level negatives risk blocking good traffic?
Yes, which is the main reason to scope carefully. An account-level negative blocks the term in every campaign, so a phrase that is junk in one campaign but valuable in another should be a campaign-level negative instead. Reserve account-level negatives for terms that are waste everywhere.