Why does my campaign show up for searches unrelated to what I sell?
Direct Answer
According to Google Ads Help, phrase match — written between quotation marks — and exact match — written in brackets — give more control and less reach than broad. Neither is inherently correct; the trade-off is between casting a wider net that needs more negatives, and casting a narrower one that needs more keyword variations written by hand.
Meaning, not spelling, decides the match
According to Google Ads Help, broad match considers the meaning of the keyword together with signals like the user's recent search activity, the content of your landing page, and other keywords in the same ad group. That is what lets a keyword like an industrial part name trigger for searches that share a topic but not an intent to buy.
For an industrial company this frequently means the ad triggering for a student researching how the part works, a technician searching for a repair manual, or a competitor comparing specifications — searches with real relevance to the topic and none to a purchase decision this quarter.
Wider reach or narrower control, never both at once
A structure that mixes the three by intent — broad for discovery on a small budget, phrase and exact for the terms that already convert reliably — tends to control cost better than an account running everything as broad by inertia.
A negative keyword does not catch its own variations
According to Google Ads Help, negative keywords do not expand to close variants — negativing one word does not automatically block its plural, its misspelling or a synonym. That means a negative list built once and never revisited slowly loses coverage as new unrelated searches appear in slightly different words.
The two moves work together: tightening match types reduces how far the ad reaches on its own, and a negative list reviewed on a schedule catches what still slips through. A ready checklist of negatives specific to industry is at the negative keywords checklist for industry.
Beyond keyword mechanics, the search intent behind a long, technical purchase cycle is treated on its own in the method page on search intent across a long cycle.
FAQ
Why does my campaign show up for searches unrelated to what I sell? +
What are the three match types in Google Ads? +
Should I switch everything to exact match? +
If I negative a word, does that block its variations too? +
What is the difference between negative broad, phrase and exact? +
How often should I review the search terms report? +
Does broad match cost more per click than exact match? +
Is broad match ever the right choice for an industrial account? +
Rebuild your match-type structure around what actually converts
The diagnosis reviews match types together with the search terms report, not one without the other.