You add "running shoes" to your campaign. A week later you're paying for "how to clean running shoes" and "history of running shoes." Nothing broke. You mixed up two things Google treats as completely separate, and the gap between them is where your budget leaks.
A keyword is your instruction. A search term is what happened.
Google's definition is simple. A keyword is a word or phrase you add to a campaign. A search term is what a person typed into Google before your ad showed up.
You write keywords. You never write search terms. Real people do that, and they type things you would never think of.
One keyword can pull in hundreds of search terms. You pick the keyword, Google decides which searches deserve it. Everything in this article lives in that gap.
Match types decide how far Google can travel
Three match types: broad, phrase, exact.
- Broad gives Google the most room. It matches on what it thinks you mean, not on your words.
- Phrase requires the meaning of your keyword to be in the search.
- Exact requires the same meaning as your keyword.
Read that last one again. Exact match stopped meaning exact wording years ago. Close variants cover plurals, misspellings, reordered words and synonyms. A keyword like [red running shoes] can serve on "crimson sneakers for marathons."
Google's language models read the intent behind a query, so all three match types stretch further than the labels suggest. Match type is not a filter. It is how tight a leash you hand Google.
One more thing to know before you switch it on: AI Max for Search goes past your keywords entirely and matches searches to your landing pages and assets. Your search terms report gets an "AI Max" match type filter so you can separate that traffic. Useful feature, but only if you watch what it brings in.
The search terms report is the only place you see reality
Find it under Campaigns → Insights & reports → Search terms.
Set your date range to the last 7 to 14 days, sort by cost, and build two mental lists: terms that spent money and converted, terms that spent money and did nothing.
You will not see every query. Google hides search terms with low volume for privacy reasons and groups them into Search terms insights as themes instead. Your report covers most of your spend, not all of your queries. Work with the expensive patterns you can see.
What to check before you touch anything
A search term isn't good or bad because of the campaign it came from. Judge every term the same way, whether it came from Search or Performance Max.
Is it relevant? Read the query as a person, not as a marketer. Could someone typing this ever buy what you sell? "running shoes for flat feet" yes. "how to lace running shoes" no.
How much did it spend? An irrelevant term that cost you $2 this month is noise. The same term at $200 is your next negative keyword.
Did it bring conversions? This one only works if your tracking is set up correctly. If your conversion fires on the wrong event, or doesn't fire at all, every decision below this line is guesswork. Fix tracking first.
What happened after the click? Look at the CPC, then open the landing page that term sent people to. If someone searches "running shoes size 13" and lands on your general shoe page, they leave. The term looks bad in the report, but the page is what failed.
What you can do with a search term
You have three options, and that's the whole list.
1. Add it as a keyword
Do this when a term converts consistently and you want direct control over its bid and its ad copy. One conversion is not a pattern. Three is a starting point.
2. Exclude it as a negative keyword
Do this when the intent is wrong and always will be: job seekers, students, people hunting for a free version, brands you don't carry.
3. Leave it as it is
Most terms end up here, and that's fine. Leaving a term alone changes nothing about how your ads run. It keeps working under the keyword that already matched it, and it stays in your report as statistics you can check again next month. You don't need to act on every line you see.
My tip: over-managing this report is a real problem. Add 40 keywords a week and you split your data across more auctions, which leaves Smart Bidding less to learn from. Add what deserves its own budget line. Exclude what wastes money. Leave the rest.
Then look at the keyword that let it in
Every irrelevant search term came from a keyword you chose. So don't stop at the terms. Once a week, sort your keywords by cost, take the biggest spenders, and open the search terms each one matched.
If one keyword eats a large share of your budget and most of the searches it pulled have nothing to do with what you sell, the keyword is the problem, not the terms. You can add negatives all month and new junk will keep arriving, because the keyword keeps opening the same door.
You have two ways out. Pause the keyword if it never brought a single relevant search. Or move it from phrase to exact, so it only picks up searches that mean what you sell. Exact costs you volume, so make that trade when the wasted spend is bigger than the traffic you would give up.
Negative keywords follow different rules
Negatives have match types too, and they block differently than positive keywords match. Say you sell running shoes and you don't want people looking for free stuff.
- Negative broad free running shoes blocks any search containing all three words in any order. That includes "free running shoes", and also "running shoes free shipping". The second one is a real customer, and you just blocked them.
- Negative phrase "free running shoes" blocks searches with those words in that order. Blocks "buy free running shoes". Lets "running shoes free shipping" through.
- Negative exact [free running shoes] blocks that exact query and nothing else. "free running shoes for men" still shows your ad.
Negatives also don't expand into close variants. Google covers casing and misspellings for you, but singular and plural count as different words: a negative "shoe" will not block "shoes." Same with synonyms.
Your account-level negative list holds up to 1,000 keywords and applies across Search, Shopping, Performance Max, App, Smart and Local campaigns at once. Use it for waste that's waste everywhere. Keep campaign-level negatives for rules that belong to one campaign only.
Performance Max has no keywords, but it has search themes
A search theme is a phrase you hand Google to point it toward the searches you want: up to 50 per asset group, 80 characters each.
A search theme reaches wider than a broad match keyword. Google gives themes the same prioritization as your phrase and broad match keywords, but a keyword still enters the auction as a keyword. A theme only points the model in a direction and lets it decide the rest. Someone can type a query that shares not one word with your theme, and PMax will serve.
Search themes are not audience signals either. Audience signals describe who you think buys from you: customer lists, in-market segments, custom segments. Search themes describe what those people search for. Both are hints. Neither is targeting, and Google will step outside both if it predicts a conversion.
You can still see what PMax matched you to. Go to Campaigns → Insights and reports → Search terms report and select "Search terms and landing pages for Performance Max." You get the actual queries, the landing page each one sent people to, and an ad format segment that separates Shopping traffic from text ads. Judge those terms with the same four questions above.
To block waste in PMax you have campaign-level negative keywords, shared negative lists, your account-level list, and brand exclusions for brands you don't sell. One limit worth remembering: negative keywords only apply to Search and Shopping inventory. They do nothing for YouTube, Display, Gmail or Discover, which need placement exclusions and the Content Suitability center.
If Performance Max is where most of your budget sits, I wrote a full guide on why PMax campaigns underperform and how to fix them.
A 15-minute weekly routine
- Open the search terms report, last 7 to 14 days, sorted by cost
- Look at the top 20 spenders with zero conversions and ask one question about each: could this person ever buy from me? If no, negative
- Look at converting terms. Anything with 3 or more conversions that isn't a keyword yet, add it
- Switch to your keywords, sort by cost, and check what the top spenders are actually matching. Pause or tighten the ones feeding junk
- Repeat the search terms steps in the Performance Max view
- Once a month, open your negative lists and remove anything you excluded on a hunch that now blocks real demand
The longer you leave it, the more of your budget goes to searches you would have blocked in the first five minutes of looking.
What you actually control
You don't decide what people type. You decide which keywords go in, how much room the match type gives Google, what gets excluded, and how fast you react to what the report shows you.
Keywords are a guess. The search terms report tells you how good that guess was. Read it every week and act on it, and your cost per conversion drops without touching a single bid.
