Every Google Ads account has a leak somewhere, and it usually looks like this: a keyword that seemed reasonable at setup is quietly pulling in clicks from people who were never going to buy. A landscaping company bidding on "lawn mower repair" instead of "lawn mowing service." A law firm's ad showing for "free legal advice" when the firm bills by the hour. The fix for most of this waste is one of the least glamorous tools in the platform: negative keywords.
A negative keyword tells Google not to show your ad when someone searches for that term, or a close variation of it. It is the opposite of a regular keyword, and it is arguably just as important, because the search terms report of almost any active account will show queries that triggered an ad but had no business doing so.
Why Negative Keywords Matter More Than They Get Credit For
Search campaigns run on broad match and phrase match by default in most modern account setups, both of which are designed to capture a wide net of related queries. That is useful for finding new demand, but it also means your ads will show for searches you never explicitly chose. Without a steady negative keyword list, a growing share of the budget ends up paying for clicks that were never going to convert.
Google's own guidance on negative keywords describes them as a way to "focus your ad on customers who are interested in what you're offering," which is a modest way of putting it. In accounts that have never had a negative list built out, it is common to find 15 to 30 percent of spend going toward search terms with zero conversions over a 90 day window.
The Three Match Types
Negative keywords use their own version of match types, and mixing them up is one of the most common setup mistakes.
A broad match negative blocks any search containing all the words in the negative keyword, in any order. Adding "free" as a broad match negative blocks "free consultation," "consultation free," and every other combination that includes the word. A phrase match negative, written in quotation marks, blocks searches that contain the exact phrase in that order, with other words allowed before or after. An exact match negative, written in brackets, only blocks the precise search term with nothing added.
Broad match negatives are powerful and dangerous in equal measure. Adding a single overly broad word can silently exclude search terms you actually wanted to reach. A retailer that adds "cheap" as a broad negative to avoid bargain hunters will also block "cheap way to ship furniture," which might describe a perfectly good customer asking about delivery options.
A Practical Starter List
Most accounts benefit from a base layer of negatives before campaign-specific ones are added. A reasonable starting point includes job-related terms like "jobs," "careers," and "salary," since people researching employment are not shopping for your product. Research-only terms such as "definition," "meaning," and "how to" often signal someone looking for free information rather than a paid service, though this depends heavily on your business model.
"Free" deserves its own line item for most service businesses, along with "DIY" for anything typically hired out to a professional. If you sell exclusively online, add location-based terms tied to markets you do not serve. If you sell locally, the reverse applies: exclude cities and regions outside your service area so budget does not leak into searches you cannot fulfill.
None of these belong on every account without judgment. A staffing agency wants the "jobs" traffic that a plumbing company should exclude. Build the starter list, then adjust it against your own search terms report rather than copying it wholesale.
This is exactly the kind of granular cleanup that separates accounts with a healthy cost per acquisition from accounts quietly bleeding budget. If your search terms report has not been reviewed in the last month, that is usually the fastest place to find savings, and it is a standing part of how Imprint's Google Ads management service runs every client account.
Where to Apply Them
Negative keywords can live at the campaign level, blocking a term across every ad group in that campaign, or at the ad group level, blocking it only within that narrower set. A common structure uses campaign-level negatives for terms that should never appear anywhere in the account, and ad group-level negatives to stop keyword cannibalization, where two ad groups in the same campaign are both eligible to show for the same search and compete against each other in the auction.
Shared negative keyword lists are worth setting up once an account runs more than two or three campaigns. Instead of adding the same exclusion to every campaign individually, a shared list applies it everywhere at once and keeps the account easier to maintain as it grows.
Building the Habit
The accounts that manage negative keywords well do not treat it as a one-time setup task. They review the search terms report on a schedule, weekly for higher-spend accounts and at least monthly for smaller ones, and they add new negatives as new irrelevant queries show up. Search behavior shifts with seasons, news events, and even algorithm changes on Google's side, so a list that was thorough six months ago can develop gaps without anyone noticing.
It also helps to keep a short log of why each negative was added. Six months from now, when a colleague or a new account manager looks at a list of forty excluded terms, "why is 'repair' blocked here" is a fair question, and a one-line note saves the time it would take to rediscover the answer from scratch.
Pair a disciplined negative keyword habit with a clear read on what you are actually spending to acquire a customer, covered in the breakdown of cost per acquisition, and you have two of the highest-leverage, lowest-cost improvements available in any Google Ads account. Neither requires a bigger budget. Both just require someone looking at the data on a regular basis.
