Negative Keywords: How to Stop Wasting Ad Spend

When you add a keyword to a Google Ads campaign, you are telling Google, "show my ad when someone searches something like this." A negative keyword does the opposite: it tells Google, "no matter what, do not show my ad when the search contains this word." It is a filter, not a trigger.

Here is why that matters for a local business with a real budget. Imagine you are a Portland plumber bidding on drain cleaning. Without negatives, Google will happily match your ad to drain cleaning jobs, drain cleaning DIY, free drain cleaning tips, and drain cleaning machine for sale. Every one of those clicks costs you money, and not one of them is a homeowner ready to book a plumber. A short negative list — jobs, DIY, free, for sale — quietly removes all of them.

Negatives do not improve your bid or your ad copy. What they do is stop the bleed, which on a tight budget is often worth more than any bid adjustment.

Certain intent words show up again and again in wasted spend. When we audit a local account, these are the categories we look for first:

• Job seekers: jobs, careers, hiring, salary, apprenticeship. Someone looking for electrician jobs is not hiring an electrician.
• DIY and information: DIY, how to, tutorial, diagram, free. These people want to do it themselves.
• Price shoppers who will never pay: cheap, free estimate is fine, but free on its own often signals someone wanting a service for nothing.
• Products, not services: for sale, parts, rental, near me store — if you sell a service, product searches waste clicks.
• Services you do not offer: a heating company that does not do oil should be negatively matching oil so it stops paying for oil-furnace searches.

None of these are universal — cheap might be fine for a discount brand — which is exactly why you build the list from your data, not a template.

Negatives have match types, but they behave a little differently from positive keywords, and the difference trips people up.

• Negative broad match (just the words, no symbols): blocks searches that contain all your negative terms in any order. It does not block synonyms or close variants the way positive broad match expands.
• Negative phrase match ("quotes"): blocks searches that contain your terms in that order.
• Negative exact match ([brackets]): blocks only that exact search, nothing else.

Two honest cautions from Google's own documentation. First, negative keywords do not automatically match close variants, misspellings, or plurals — so if you negative-match job, searches for jobs can still slip through. Add both. Second, be careful with multi-word negatives: a negative phrase of "free repair" will only block searches containing that whole phrase, not searches with just free. When in doubt, start with single-word negative broad terms for the obvious drains and get more surgical from there.

The single most valuable screen in Google Ads for controlling waste is the search terms report. It shows the actual queries people typed before they saw your ad — not the keywords you bid on, but the real-world searches Google matched to them.

A practical weekly or monthly routine looks like this:

• Open the search terms report and sort by cost or clicks.
• Read down the list and flag anything irrelevant — wrong service, wrong intent, wrong location, job seekers, DIYers.
• Add those terms as negatives, usually at the campaign or account level so they protect everything.
• Keep a shared negative keyword list that you apply across campaigns, so common junk is blocked everywhere at once.

This is not a one-time setup. New irrelevant searches appear constantly, especially with broader match types. Fifteen minutes of pruning a month is often the highest-return work in a small account.

Negative keywords are the defensive half of keyword management. The offensive half is choosing the right match types for your positive keywords so you reach real buyers without casting too wide a net. The two work together: broader positive matching finds more customers, and a disciplined negative list keeps that reach from turning into waste.

On a modest local budget, this discipline is not optional — it is the difference between a campaign that pays for itself and one that quietly burns money on searches that were never going to call. If you would rather have someone build and maintain that discipline for you, that is a core part of how we run paid advertising for Maine service businesses. Have questions about your own wasted spend? Get in touch.