As Google Ads has automated, the list of things you genuinely control has shrunk. Bidding is algorithmic, targeting is increasingly a suggestion, and placements are chosen for you. What is left, almost entirely, is the ability to say no.
Which makes it worth knowing exactly how the no works. There are four separate exclusion systems, they operate on different things, and they live at different levels of the account. Apply one at the wrong level and it silently does nothing, which is the single most common way we find budget leaking in audited accounts.
The four systems, and where each one lives
This table is the whole guide compressed. Everything below is detail.
| Control | Campaign level | Account level | Acts on |
|---|---|---|---|
| Negative keywords (Search, Shopping) | Yes | Yes | Queries |
| Negative keywords (Performance Max) | Yes | Yes | Search + Shopping inventory only |
| Placement exclusions (Display, Video, YouTube) | Yes | Yes | Sites, apps, channels |
| Placement exclusions (Performance Max) | No | Yes (+ MCC) | Sites, apps, channels |
| Content suitability / inventory type | — | Yes | Content sensitivity |
| Audience exclusions | Yes | Yes | People |
The highlighted row is the one that costs money. We will come back to it.
Negative keywords, and what changed in Performance Max
Negative keywords are the oldest control in the account and still the most useful. They act on the query, not the keyword you bid on, which is why the search terms report is where the work actually happens rather than the keyword list.
The part worth updating your mental model on: Performance Max now accepts campaign-level negative keywords, and negative keyword lists can be applied to PMax campaigns too. For a long time this was not possible, and a lot of advice still assumes it is not.
But read the limit carefully, because it is where people get caught: negative keywords in PMax apply to Search and Shopping inventory only. They do nothing to Display, Video or YouTube placements. If your PMax campaign is bleeding into mobile game apps, no quantity of negative keywords will stop it. That is a placement problem and it needs a placement tool.
Account-level negative keywords behave differently again: they apply automatically across all Search and Shopping inventory, including inside your PMax campaigns. Useful for the permanent list · competitor brand terms you never want, job-seeker queries, "free", "cheap", "salary".
Placement exclusions, and the Performance Max exception
Placement exclusions stop your ads serving on specific sites, apps, whole app categories, YouTube channels and individual videos. For most campaign types you set them at campaign level and they work as you would expect.
Performance Max is the exception, and it is the important one. There is no campaign-level placement exclusion for PMax. Google's documentation is explicit that PMax respects account-level and MCC-level placement exclusions only. Set them on the campaign and nothing happens · no error, no warning, just budget continuing to flow into the inventory you thought you had blocked.
The path is Tools → Content suitability → Advanced settings → Excluded placements. Account level, every time, for PMax.
This is why a B2B account running PMax quietly funds mobile games, live-score apps and resale marketplaces. In-app banners and interstitials generate a steady drip of accidental clicks, none of which will ever become pipeline. We walk through the full fix in Performance Max is leaking your budget into mobile apps.
The two-layer habit
Placement work is not a setting you apply once. It is recurring hygiene, and it has two layers.
- Layer 1, the blunt cut. Exclude whole app categories that could never contain your buyer · games, dating, kids and family, and the rest of the consumer grab-bag. Fast, imprecise, and it stops the worst of the bleed on day one.
- Layer 2, the placement report. Open "Where ads showed" under Insights and reports, weekly. Look at the actual apps and sites your ads served on, select the junk, and exclude at account level. Then do it again next week, because new placements never stop appearing.
Layer 2 is the one teams skip, and it is the one that compounds.
Content suitability is a different lever
Content suitability does not exclude specific places. It controls how sensitive the surrounding content is allowed to be, across YouTube, Display and Google Video Partners. Its main control is inventory type, and Google renamed all three: Maximum (was Expanded), Moderate (was Standard) and Limited. The exclusions did not change with the names.
Alongside it sit the sensitive content categories · tragedy and conflict, sensitive social issues, profanity, sexually suggestive content, sensational and shocking material · which you can exclude independently of the inventory tier.
Two things to understand before you reach for it. Google's Video Ad Safety Promise applies at all three tiers, so the genuinely controversial content is excluded regardless of your setting. And tightening costs you reach: Google's own estimate panel shows reduced inventory, reduced impressions and an increased CPM, because a smaller pool is more expensive to buy. We compare the tiers in Google Ads inventory types explained.
It is a blunt instrument, and it is no substitute for the weekly placement review.
Audience exclusions: the one almost nobody uses
The three systems above act on queries, places and content. The fourth acts on people, and it is the most underused control in paid search.
Your CRM already holds a verdict on who wastes your budget: the spam, the tyre-kickers, the competitors doing research, the leads sales qualified out. Pull that list, upload it to Google Ads as a Customer Match customer list, and apply it as an audience exclusion. The people your own team already rejected stop costing you money.
The detail that makes this available to everyone: using Customer Match for exclusions carries no spend requirement to unlock. Full walkthrough in stop paying to re-acquire the leads your sales team already rejected.
The judgment layer: do not over-exclude
Everything above is a way of saying no, and saying no is not free. This is where we part company with the reflex to exclude aggressively.
Google's own guidance on PMax negative keywords is to use them for essential brand safety and clearly irrelevant terms, because heavy restriction prevents the system from finding valuable traffic. That is self-serving advice from a platform that profits from breadth, and it also happens to be right more often than not.
Our working rule: a zero-conversion placement or query is not automatically waste. Exclude when a term or placement is genuinely off-intent, or when the spend is large enough to be a statistically meaningful drain. Excluding a placement that has spent $4 is noise-fitting, and thirty of those decisions add up to a campaign strangled by its own exclusion list.
The asymmetry worth remembering: an account with no negative keywords at all is nearly always broken, while an account with thousands of them is often broken in a subtler way.
The takeaways
- Four exclusion systems, four levels. Applying one at the wrong level fails silently.
- Performance Max takes campaign-level negative keywords now, but they only affect Search and Shopping inventory.
- Performance Max has no campaign-level placement exclusion. Account or MCC level only, via Tools → Content suitability.
- Content suitability controls sensitivity, not specific placements, and tightening it raises your CPM.
- Audience exclusions from CRM data have no spend gate, and almost nobody uses them.
- Zero conversions is not proof of waste. Exclude off-intent and significant drains, not everything that has not converted yet.