Most wasted ad spend doesn't come from bidding too high or writing weak copy. It comes from paying for clicks that were never going to become customers, and the tool that stops that bleeding is the most boring item in the whole platform: the negative keyword list. If you run search ads for an HVAC, plumbing, roofing, cleaning, or med spa business and you've never built a serious negatives list, this single edit can recover a meaningful chunk of your budget overnight.

What Negative Keywords Actually Do

When you bid on a keyword like "ac repair," Google doesn't only show your ad for that exact phrase. Depending on your match types, it shows your ad for a sprawling web of related searches, and many of them are garbage. People searching "ac repair jobs," "ac repair training course," "how to ac repair yourself," or "ac repair free" will see your ad, click it, and cost you money while having zero intention of hiring anyone.

A negative keyword tells Google to never show your ad when that word or phrase appears in the search. It's a filter, and it's the difference between paying for buyers and paying for tire-kickers, students, and competitors.

The Universal Negatives Every Service Business Needs

These apply to nearly every local trade. Add them before anything else.

Job seekers: jobs, careers, hiring, salary, apprenticeship, employment, "near me jobs," resume. People looking for work outnumber people looking for service on many trade keywords, and they convert at zero.

DIY and how-to: how to, DIY, yourself, tutorial, fix it myself, instructions, "step by step," YouTube. These searchers want to avoid hiring you, by definition.

Free and cheap-only: free, cheapest, discount code, coupon, "for free," "no cost." Some discount language is fine, but pure freebie-hunters rarely become real customers.

Education and licensing: course, training, school, certification, license, exam, classes, degree. Aspiring tradespeople, not clients.

Information and research: wiki, definition, meaning, reddit, "what is," history, images, pictures. Pure research intent.

Used, rental, and product-only: used, rental, rent, parts, "for sale," manual, warranty (when you're selling service, not products).

Trade-Specific Negatives Worth Stealing

The universal list is the foundation. Then you layer on negatives for your specific business.

HVAC: Add "window unit," "portable," and specific big-box retailer names if you only do installs and service, not unit sales. Add "car," "automotive," and "vehicle" because car AC searches will absolutely leak in.

Plumbing: Add "snake rental," "Drano," "home depot," and "lowes" if you don't want DIY-product traffic. Add "school" and "supply" to dodge plumbing-supply stores.

Roofing: Add "shingles" used as the medical condition (it happens more than you'd think), "minecraft" and "game" for roof-design game searches, and "insurance" if you don't handle claims.

Cleaning: Add "products," "supplies," "equipment," "vacuum," and "robot" to filter people shopping for tools instead of a service. Add "jobs" with extra emphasis because cleaning job searches are enormous.

Med spa / aesthetics: Add "at home," "device," "kit," "DIY," and "gone wrong." Add "before and after" cautiously, since some of that is research traffic rather than buyers ready to book.

How to Find Your Own Negatives

The stolen list gets you most of the way, but your search terms report writes the rest of your negatives for you. This is the report inside Google Ads that shows the actual phrases people typed before clicking your ad, as opposed to the keywords you bid on. Review it weekly at first. Every irrelevant phrase you spot becomes a new negative. After a month or two of disciplined pruning, the junk slows to a trickle and your cost per genuine lead drops noticeably.

A practical tip: build a shared negative keyword list at the account level so every campaign inherits your universal negatives automatically. Then keep campaign-specific lists for the trade quirks. This way you maintain the list in one place instead of duplicating it everywhere.

The Mistake That Cancels It Out

Be careful not to over-prune. Negatives are permanent until you remove them, and an aggressive negative can silently block real customers. For example, blocking "repair" to dodge "repair jobs" would also block "ac repair," your best keyword. Always think about what legitimate searches a negative might catch before you add it, and prefer phrase-match negatives over broad ones when there's any risk.

Why This Matters More Than Bid Tweaks

Owners love to fiddle with bids and budgets, but those are small levers compared to simply not paying for the wrong people. A clean negative list improves your click-through rate, which improves your Quality Score, which lowers your cost per click, which stretches the same budget over more real prospects. It compounds. One afternoon of work keeps paying you back for months.

If you'd like a set of eyes on your search terms report, we do this constantly. Book a free 30-minute strategy call with Veyri Labs and we'll review where your ad budget is leaking and hand you a negative list tailored to your trade, whether or not you ever hire us.