Negative lists hold the negative keywords you attach to multiple campaigns because the related search terms are so damaging to ROAS, so full of wasted spend, that you want to block them across various parts of the account.
The problem is that negative lists tend to be added to and not subtracted from. New keywords are added over the years, but old ones are rarely removed.
But some of those negative keywords are no longer helpful.
There are a few specific ways this happens:
The business model changed. The client moved upmarket, downmarket, or cross-market by adding a product category, launching a new service, or starting to sell to a different customer base. Queries that had to be negated because they didn’t lead to sales would now be valid.
Search behavior evolved. The intent behind queries can shift over time. A term that attracted tire-kickers in 2020 (“what AI tool can I buy for X”) might now correlate strongly with purchase intent because the entire product circumstance has changed (now there are decent AI products for X). The search landscape in many niches can easily look meaningfully different than it did a few years ago.
The competition got nerfed. A dominant competitor exited the market. A niche that was too crowded to touch has opened up because competitors no longer bid heavily on the related search terms. Terms that weren’t worth bidding on for your client, because competitors would always outbid you, may now return good ROAS.
The original rationale for negation cannot be found. Someone added a negative for a reason that seemed obvious at the time, then moved on. The reason can’t be found anywhere in your documentation. Two years later, nobody knows whether the negative is still reasonable, so nobody touches it.
Early negation was too aggressive. When an account is new, the instinct is to lock things down tight. Broad blocks get applied to whole categories just to be “safe.” A phrase-match negative for “free” doesn’t just block “free food” or “food with free shipping.” It blocks any query containing “free”: “gluten free,” “dairy free,” “salt free.” If your client sells food products and there was an early phrasal negation of “free” just because that term was associated with very poor ROAS, someone should have made a note once the account had settled. The note: to evaluate whether certain word combinations involving “free” were truly wasteful and whether some sub-niches had the potential to be quite profitable.
When to Delve into Your Negative Lists
The right trigger for a negative keyword review is change, either in the business or in the client’s expectations.
The clearest signal is a known business change: a new product line. Any time the business materially changes what it sells or who it sells to, the negative list should be revisited to find exclusions that no longer fit.
Another trigger is time-based. It may simply be time for a review because the existing negative keywords have been sitting in that account for a growing number of years. Lists that were built two or more years ago should be treated as candidates for re-examination, simply because of how much can change in that time.
What to Look For
Not every negative on the list is worth scrutinizing. There might be many thousands of them, and examining every one in reasonable depth would take ages. There are far more productive activities you could spend your time on that would better serve the health and revenue of the account than negation research alone.
The goal of a review is to find the terms most likely to have changed in relevance, as discussed above.
The highest-priority candidates are negatives that align directly with the type of business changes we’ve already discussed. If your client has added a wholesale program, look at negatives like “wholesale,” “bulk,” and “distributor.” If your client has expanded into a new product category, look for category-level negatives that were applied when that category didn’t exist.
Also worth scrutinizing: negatives that block a large number of query variations. A phrase-match negative for a single word, such as “long,” can block dozens or hundreds of search terms, only some of which might be wasteful (such as “long fingered gloves” for a certain client). If the logic behind that broad block no longer applies, the cost of keeping it is significant.
Lower-priority candidates, terms that are usually safe to keep, include clearly irrelevant queries for the account’s niche (job listings, career searches, and similar terms for retail accounts), well-documented negatives that were tested, found to underperform, and negated with supporting data (and where no business update contradicts them), and very specific long-tail exact-match negatives that block minimal traffic regardless of whether they’re still valid. Spending ten minutes evaluating a term that costs $5 a year won’t move the needle.
Also, leave alone negatives that exist to route traffic between campaigns rather than to block bad traffic entirely. Many campaign structures use negatives not because a query is worthless, but because it should be handled by a different campaign with different targeting or bid targets. These are architectural decisions, not legacy candidates. You might block terms containing “above ground” in an in-ground swimming pool campaign, for instance.
Before You Remove Anything: Where to Find Persuasive Evidence
Identifying a strong candidate is one thing. Deciding whether to actually remove that keyword can involve more than intuition.
Google Ads Change History. Before removing a negative, check when it was added and whether there’s any annotation explaining why. A negative added four years ago with no note is a different proposition than one added six months ago with a comment referencing a specific reason for the negation.
Google Keyword Planner. This free tool inside Google Ads lets you check the current search volume for any term you’re considering un-negating. It clarifies whether the negative keyword under consideration is likely to drive $1,000 a month in spend across 2,000 ads or just $10 a year across 5.
Your own Search Terms report. This shows the actual queries triggering your ads now, but it can also show you what used to appear before a negative was added (clicks and conversions) if you look at historical date ranges. Usefully, it also tells you whether related queries, ones that aren’t negated but are adjacent to the term you’re reviewing, are converting. If searches semantically close to your candidate are generating revenue, that’s a meaningful signal about the likely value of the blocked term.
Taken together, these data points let you move from intuition (“this probably should be un-negated”) to a reasoned position (“volume is growing, the business now sells this, and the original negation was based on twenty clicks in 2021”).
You’re Running a Test, Not Flipping a Switch
When you identify a likely candidate, the temptation is to simply remove the negative and hope for the best.
The correct approach is to remove the negative with a clear commitment to review performance within a defined timeframe, typically two weeks, though more frequently for terms likely to generate significant traffic quickly and less frequently for lower-volume terms.
Before un-negating, decide in advance what “bad” looks like. How many clicks, or how much spend, with zero conversions would trigger immediate re-negation? What cost-of-sale threshold would indicate the term is underperforming? What timeframe are you giving the test before making a call?
Higher-risk un-negations, including broad terms, high-volume queries, and categories adjacent to expensive mistakes… should be staggered rather than implemented all at once.
During the monitoring period, the most important thing to watch is the actual search terms now being triggered. The point of negative keywords is to block specific queries, not entire concepts. Removing a negative often reveals unexpected query variations that need to be individually re-negated.
What Good Un-Negation Looks Like
A successful un-negation test does two things: it recovers revenue that was being blocked, and it can reduce bloated negative lists into ones that are more understandable and relevant.
When a term performs well after un-negation, briefly note the outcome. What type of negative was it? What was the original rationale? What changed? This prevents the same over-negation decisions from being made again.
When a term performs poorly and gets re-negated, that’s also a useful outcome. You’ve confirmed the original decision was correct.
The goal isn’t to remove as many negatives as possible. It’s to make sure that every key negative on your list is there for a reason that still applies today. A periodic review won’t make an account and its negative lists perfect, but it keeps the inefficiencies under control.
Mike Jelley
Mike studied Computer Science, then worked in a Management Information Reporting role, switched to a Data Analysis role, and then Paid Ads Campaigns Management in a results driven environment... before joining StatBid. Outside of StatBid he is kept busy by his wife, son and fur babies. Enjoys Sci-fi and fantasy in both novel and 'on screen', and supports Tottenham Hotspur FC.
