Negative Keywords: Building a List That Pays for Itself

Adding negatives is the first thing anybody learns to do in Google Ads and one of the last things anybody learns to do properly. The mechanics are not intuitive, the match types behave differently from their positive counterparts, and a list built carelessly will block sales you wanted while letting through the rubbish you were trying to stop.

Negatives do not behave like keywords

This is the part that catches experienced advertisers out.

Negative broad blocks a query only if every word in your negative appears somewhere in it, in any order. Negative broad free quote blocks “free quote for a new boiler” but does not block “free boiler”.

Negative phrase blocks a query containing your words together, in that order, with anything either side.

Negative exact blocks only that precise query and nothing else.

Now the important bit: negatives are literal. Unlike positive keywords, they do not expand to close variants. Blocking job does not block “jobs”. Blocking courses does not block “course”. Misspellings are not covered either. If you want plurals and the common misspellings stopped, you add them as separate lines. Most disappointing negative lists are disappointing for exactly this reason.

One further quirk: negatives do not match against implied meaning. Google’s matching system is increasingly good at understanding intent on the positive side and remains a word-matching system on the negative side. That asymmetry is why you can never fully block a concept — only its vocabulary.

Where to put them

Three levels exist and they are not interchangeable.

Ad group. Applies only within that ad group. Its real use is routing rather than blocking — stopping traffic that belongs in one ad group from being served by another, so that each theme gets the ad copy written for it.

Campaign. The normal home for anything specific to that campaign’s offer or geography. A campaign holds a large number of negatives, well beyond what most accounts will ever need, so running out of room is rarely the constraint.

Shared lists. Built under the shared library and then applied to whichever campaigns you choose. This is where your permanent, account-wide exclusions belong, because updating one list updates every campaign it is attached to. Build these as themed lists — one for job seekers, one for free and DIY, one for adjacent services you do not offer — rather than one enormous list, so you can attach different combinations to different campaigns.

There is also an account-level negative list. It applies everywhere with no exceptions, and it holds far fewer terms than a campaign does, so reserve it for things that must never run anywhere: adult terms, a competitor you have a legal reason to avoid, a discontinued product line.

Check where existing negatives live before adding more. Inherited accounts routinely have the same fifty terms duplicated across every campaign, at which point nobody dares change anything.

Which categories to block first

Order matters, because the first four categories usually account for most of the recoverable waste.

1. Price-avoidant intent. Free, cheap, DIY, “how to”, “yourself”, second-hand. People who want to do it themselves are not going to pay you to do it.
2. Jobs and careers. Job, jobs, vacancy, vacancies, salary, apprenticeship, recruitment, CV, “hiring”. Every service business gets these and almost none of them convert.
3. Learning rather than buying. Course, courses, training, qualification, certification, diploma, tutorial, “what is”. These queries are enormous in some sectors.
4. Wrong geography. Towns, counties and countries you do not serve. This works alongside your location settings rather than instead of them, and it catches people physically in your area searching about somewhere else.

After those, the sector-specific ones:

• Adjacent services you do not offer. A studio doing website builds gets queries for hosting support, domain transfers and logo competitions.
• Homonyms and collisions. Anything where your service noun means something else to somebody else. Worth reading a hundred search terms specifically hunting for these.
• Research and reference. Wikipedia, Reddit, forum, PDF, template, examples, images, meaning, definition.
• Competitor names, with a caveat below.

Competitor terms, and other decisions that are not obvious

Blocking competitor names is a default habit rather than a considered choice. Sometimes people searching a rival’s name are genuinely comparing and will consider you; those clicks are expensive and convert poorly, but not never. The honest answer is that it depends on your margin and how different your offer is. Test it before you decide, rather than blocking it because a checklist said so.

The bigger risk in most accounts is not under-blocking, it is over-blocking. A broad negative for cost looks sensible until you notice that “boiler replacement cost” is a strong buying query. A negative for near me — yes, people do this — removes the highest-intent local searches there are.

Two habits prevent this:

• Prefer phrase and exact negatives to broad ones when the word could appear in a legitimate query. Block free templates, not free.
• Check the conversion data on the term before blocking it. If a term you were about to exclude has ever produced an enquiry, stop and think.

If you are ever unsure whether a negative is blocking your own targeting, Google Ads Editor will flag conflicts between a negative and a keyword you are actively bidding on. It is worth running that check on any account you have inherited.

Automated campaign types

Negative keywords now apply to Performance Max at campaign level as well, which was not always true. Two things to understand about them there. They act on the search and shopping inventory the campaign uses — they do not police video, display or Discover placements, which have their own exclusion controls. And brand exclusion lists are a separate mechanism from negatives, aimed specifically at keeping shopping and search inventory away from named brands.

Maintenance, and knowing when to stop

Run the exercise weekly while a campaign is new, monthly once it settles, then quarterly. The returns decline sharply. After a few months a well-built list stops earning much, and an agency still billing for “negative keyword optimisation” a year in is billing for a task that finished.

The tell that something is structurally wrong: if you are adding dozens of negatives every month and the same categories keep reappearing, the list is not the problem. Your match types are too loose, or your ad groups are too broad, or you are asking broad match to work without the conversion data it needs to steer. Fixing that upstream removes the need for most of the downstream blocking.

Negatives are a filter, not a strategy. They stop you paying for the wrong audience. They do nothing whatsoever to make the right audience buy — that is a job for the offer, the page and the follow-up. If your account is clean and enquiries are still thin, the next place to look is what happens after the click.