How negative keywords actually work
A negative keyword is an instruction not to show. Where a normal keyword tells Google which searches to enter, a negative tells it which to skip. They can be applied at the ad group, campaign, or account level, and stored in shared lists reused across campaigns. Like normal keywords they have match types, which is where most mistakes happen: a broad negative for shoes will block any search containing that word, including ones you wanted, so the match type of a negative deserves as much thought as the match type of a keyword.
Why negatives are the guardrail on automation
Broad match and Performance Max are built to expand into related searches, and that expansion is only as safe as the negatives fencing it. Without a disciplined negative list, automated matching will steadily enter auctions for the wrong intent: bargain queries against a premium product, job-seeker queries against a service, competitor names you do not want to pay for. Negatives are how you keep the reach without the waste. iClick treats the negative list as the steering wheel of an automated account, not a set-and-forget setting.
Where the list comes from: search terms hygiene
Negatives are not brainstormed once at launch; they are harvested continuously from the search terms report, which shows the actual queries that triggered your ads. Each review pulls the irrelevant terms into the negative list and, occasionally, promotes a strong performer into a real keyword. iClick runs this on a weekly cadence on active accounts, because the queries automated matching finds drift over time, and a list built at launch and never touched is stale within a month.
The two ways negatives backfire
The first mistake is too few: a thin list lets automated matching wander, wasting spend and feeding the bidding model bad conversion data. The second is too aggressive: over-broad negatives silently block valuable searches, and because the block is invisible on the dashboard, nobody notices the traffic that never arrived. The discipline is precise negatives harvested from real search data, reviewed for the queries they might unintentionally exclude, and layered at the right level so a campaign-wide block does not kill one ad group's best term.
