Most Google Ads accounts have a negative keyword list. Very few have a negative keyword strategy. The difference shows up in wasted spend, declining CTR, and Search Terms reports full of obvious mismatches that have been sitting there for weeks. (Based on common patterns observed in Google Ads account reviews; formal benchmarks on this specific metric are not widely published.)
Here is how to build a negative keyword system that grows with your account rather than falling apart the moment you add a new campaign.
Why Most Negative Keyword Lists Stop Working
A list built at campaign launch is a snapshot. It captures the bad queries your team knew about before the account went live. Three months later, it is outdated.
The failure mode looks like this: you build a tight initial negative list, launch, and then let the account run. The Search Terms report fills up with new mismatches, but nobody has a scheduled process to review it. The account scales, you add campaigns, and suddenly each campaign has its own disconnected negative list, or none at all. Inconsistency creeps in. The same bad query is blocked in Campaign A and invisible in Campaign B.
The other failure mode is over-blocking. A practitioner adds negative broad match keywords indiscriminately and starts killing legitimate traffic without realizing it. Revenue drops. The diagnosis takes weeks.
Neither problem is about having too few negatives. Both are about having no system.
How Negative Match Types Actually Work (This Confuses Everyone)
Google Ads has three negative match types, and they behave differently from positive match types. Knowing the difference is not optional. (See Google Ads Help: Add negative keywords to campaigns for current documentation on negative match type behavior.)
Negative broad match blocks any query that contains all of the words in your negative keyword, in any order. Add "running shoes" as a negative broad match and you block "cheap shoes for running," "shoes running trail," and "running women's shoes" as long as both words appear. This sounds useful, but it is overly blunt. It will also block queries you want. Negative broad match is rarely the right tool; use it only when you are certain you want to exclude every query containing all of those words, regardless of context.
Negative phrase match blocks any query containing the exact phrase in order. Add "running shoes" as a negative phrase and you block "cheap running shoes," "running shoes for women," and "on sale running shoes," but not "shoes for running" (the word order is reversed) or "trail running gear" (the phrase does not appear). This is the workhorse of negative keyword strategy. It gives you precision without the over-blocking risk of broad match.
Negative exact match blocks only the precise query. Add [running shoes] as a negative exact match and only searches for literally "running shoes" are blocked, nothing else. Use this for specific branded terms, competitor names, or queries where you want to exclude one form but not related variations.
A practical rule: start with phrase match. Add exact match when you need a surgical exclusion. Avoid broad match unless you have a clear reason and you have verified the blast radius.
Campaign Level vs. Ad Group Level: The Decision Logic
Where you apply a negative keyword determines what it blocks.
Campaign-level negatives apply to every ad group in that campaign. A query blocked at the campaign level cannot trigger any ad in that campaign, full stop. Use campaign-level negatives for category-wide exclusions: queries that have nothing to do with any product or service the campaign covers. If your campaign sells B2B software and you are picking up "how to code for free" queries, that belongs at the campaign level. No ad group in that campaign should serve those searchers.
Ad-group-level negatives apply only within one ad group. This is where the logic gets more nuanced. Say you sell both running shoes and hiking boots, split into separate ad groups. The keyword "boots" may be fine for your hiking ad group but a mismatch for running shoes. You add "boots" as a negative at the ad group level in the running shoes group, not the campaign level, because you still want it to trigger your hiking ads.
The decision logic is simple: if the exclusion applies to the entire campaign, apply it at the campaign level. If the same query is relevant in one ad group but not another, apply it at the ad group level. Applying ad-group exclusions at the campaign level is one of the most common over-blocking mistakes in managed accounts.
Shared Negative Keyword Lists: The Real Scale Play
If you manage more than a few campaigns, maintaining separate negative lists per campaign is how you end up with inconsistency and missing coverage. The solution is shared negative keyword lists.
In Google Ads, go to Tools, then Audience Manager, then Negative Keyword Lists (or via the Shared Library). Create a list once, then apply it to as many campaigns as you want. When you update the list, the change propagates to every campaign it is applied to automatically. You do not have to touch each campaign individually.
This is how you scale a negative keyword strategy. Accounts managing multiple campaigns typically see the largest efficiency gains, eliminating the need to maintain parallel per-campaign negative lists. It has three practical implications:
- Build lists by theme, not by campaign. A "competitor brand terms" list. A "job seeker queries" list. A "free/DIY intent" list. Each list covers a category of bad traffic that applies across multiple campaigns.
- Apply lists at the campaign level. Shared lists attach to campaigns, not ad groups. This means they function as campaign-level negatives for every ad group in those campaigns. Plan accordingly.
- Audit the lists on a schedule, not on a feeling. A list you built eight months ago may contain outdated exclusions or be missing new patterns that have emerged. Set a calendar reminder to review each shared list quarterly.
One caution: shared lists cut both ways, which means mistakes propagate at scale too. Before adding a new keyword to a high-traffic shared list, check whether it could block legitimate queries in any of the campaigns the list is applied to. The Search Terms report and a quick impression-share check are your diagnostic tools here.
The Audit Loop: When to Check and What to Add
A negative keyword strategy without an audit loop is just a snapshot. The loop is what makes it a system.
Frequency: Pull the Search Terms report weekly for active campaigns, bi-weekly for lower-spend accounts. Campaigns in competitive or broad-match-heavy accounts need weekly attention. Campaigns running only exact match can tolerate a longer interval.
What to filter for:
- Queries with zero conversions over the last 30 days and more than 10 impressions (10 impressions provides a minimal signal floor; below that volume, data is too sparse to distinguish a targeting mismatch from normal variation)
- Queries with CTR below your account average (suggests the ad copy is a mismatch for the intent)
- Queries with high spend and low conversion rate relative to your target CPA
What to add:
- Queries that are categorically off-topic (wrong industry, wrong intent, wrong geography if not using location targeting to cover it)
- Branded queries from competitors you are not specifically running competitor campaigns for
- Job-seeker and academic queries ("how does X work," "X salary," "learn X") if your campaigns target buyers, not researchers
- Navigational queries for your own site (searchers looking for your homepage should find it organically, not cost you a click)
How to add them:
Decide on match type before you add. Most candidates belong in phrase match. Copy the query from the Search Terms report, decide whether it belongs at the campaign level or ad-group level, and add it. If the same term belongs in multiple campaigns, add it to the appropriate shared list instead.
What not to add:
Do not add negatives reflexively. A query with zero conversions over 10 impressions in one week is a data point, not a verdict. If the query is relevant to your product, the problem may be the ad copy or landing page, not the targeting. Add negatives when the query is categorically wrong, not just underperforming.
Negative keyword strategy is one of those account management tasks where the payoff is invisible when it is working. Spend stops leaking. Quality Score stabilizes. CTR trends up. None of that shows up as a win in a dashboard; it shows up as the absence of waste.
The shared list structure, applied consistently with a weekly audit loop, is what separates accounts that stay clean at scale from ones that require a quarterly overhaul.
Related guides: Negative Keyword Audit guide · Common Google Ads Keyword Mistakes · Match Type Coverage tool.
If you want to surface the gaps in your current negative keyword coverage before your next audit, run your active Search Terms data through the Negative Keyword Gap Finder at keywordplannertools.com/negative-keyword-gaps/. It flags query patterns that are costing spend without generating conversions, sorted by match type.
Published on KeywordPlannerTools.com by David Pedersen (SEMalytics). KeywordPlannerTools.com is an independent tool site; no affiliation with Google.