How to Choose Keywords for Google Ads

Choosing keywords is the most consequential decision in any Google Ads campaign. Get it right and your ads appear in front of people who want exactly what you offer, at the moment they are ready to act. Get it wrong and you burn budget on traffic that never had any intention of becoming a customer. The difference between these two outcomes is almost never luck.

Effective keyword selection is a research process built on customer understanding, data validation, and structural discipline. This guide covers the complete process: understanding intent tiers, mastering match types, grouping keywords for maximum Quality Score, and building a negative keyword list that protects your budget from day one.

Not all keywords are created equal. Transactional keywords represent 15% of searches but deliver 80 to 90% buying intent. Bid accordingly.

Why Keyword Choice Determines Campaign Profitability

Every keyword in your campaign is a hypothesis: 'someone who types this phrase is likely to become my customer.' The job of keyword research is to validate that hypothesis with data before you commit budget to it. A keyword with 2,000 monthly searches and 5% buyer intent generates fewer paying customers than one with 200 searches and 80% buyer intent.

This insight shifts keyword selection from a volume-maximisation exercise to a precision exercise. You are not looking for the keywords that will generate the most clicks. You are looking for keywords that will generate the most conversions per dollar spent. These are often less obvious, more specific, and less competitive than the broad terms that seem like obvious choices.

For Melbourne-based service businesses, this precision principle is especially important. A plumber targeting 'plumbing services' nationally wastes budget on searches from Perth, Brisbane, and Sydney. The same budget pointed at 'emergency plumber Carlton' and 'plumber South Melbourne same day' reaches the right people with urgency-driven intent at a fraction of the wasted national cost.

The structural consequence of good keyword selection is also significant. Keywords chosen for intent alignment group naturally into tightly themed ad groups, which achieve higher Quality Scores, which lower CPCs. The whole campaign architecture improves when you start with intent-based keyword research. For the optimisation side of this equation, read our companion guide on how to optimise keywords for Google Ads success.

Understanding Search Intent: The 3-Tier Model

Every search query reveals something about the state of mind of the person typing it. Keyword research that ignores intent is just keyword research. Keyword research that accounts for intent is campaign strategy.

Informational intent searches want knowledge. 'How does Google Ads work', 'what is a Quality Score', 'Google Ads explained'. These searchers are months away from buying. Bidding on them typically produces CTRs below 1% and conversion rates near zero. They belong in a content marketing strategy, not a direct response campaign.

Commercial intent searches are comparing options. 'Best Google Ads agency Melbourne', 'Google Ads vs SEO', 'compare PPC services'. These searchers are evaluating. They may convert on the first visit, or they may need to be retargeted. Bid at moderate levels and send them to a well-structured service comparison page.

Transactional intent searches are ready to act. 'Hire Google Ads specialist Melbourne', 'Google Ads management pricing', 'Google Ads agency near me'. These searchers have identified their need, shortlisted their options, and are ready to make contact. These are your money keywords. Bid aggressively, point them to a fast-loading, mobile-optimised landing page with a single clear CTA, and track every conversion.

Match type selection is as important as keyword selection. Incorrect match types can waste 40 to 60% of a campaign budget within the first month.

Building Tightly Themed Ad Groups for Maximum Quality Score

An ad group is a container within your campaign that groups related keywords together and connects them to a specific set of ads and a specific landing page. The rule for high-performing ad groups is one theme per group. A theme means the keywords all describe the same specific service, intent, or customer problem.

Consider a web design business in Melbourne. A tight ad group might contain: 'web design Melbourne', 'website design Melbourne', 'Melbourne web designer', and 'web design company Melbourne'. These four terms share the same geographic intent, the same service category, and can all be addressed by an ad headline containing 'Web Design Melbourne' and a landing page with 'Melbourne Web Design Services' in the H1. All three elements, keyword, ad, and landing page, point at the same thing. Quality Score rewards this alignment.

A poorly structured version of the same account might put 'web design', 'logo design', 'SEO Melbourne', and 'social media management' in the same ad group, sending all traffic to the homepage. The ad cannot include all of those themes in the headline. The homepage is relevant to none of them specifically. Quality Score suffers, CPCs rise, and conversion rate drops because users arrive at a page that does not match what they searched for.

For a new campaign, the practical guidance is five to fifteen keywords per ad group and no more than five to eight ad groups to start. A small, tightly structured campaign collects cleaner data and is far easier to optimise than a large, sprawling one. Book a free call if you want us to review your ad group structure before launching.

Negative Keywords: The Pre-Launch Protection Every Campaign Needs

A negative keyword tells Google never to show your ad when a search query contains that term. Negative keywords are the most cost-effective optimisation you can make to any campaign and the most consistently neglected by first-time advertisers. Running a campaign without negative keywords is like running a retail store with no qualifying conversation at all: you end up talking to everyone and converting almost no one.

Build your negative list from four logical categories before launch. Intent signals: free, cheap, affordable, discount, no cost, budget, reduced. Research/learn intent: how to, DIY, tutorial, guide, course, training, learn, explained, what is. Employment searches: jobs, careers, salary, vacancy, hiring, internship, graduate, employment. Adjacent categories: any service or product you do not offer that might be loosely associated with your keywords.

Once the campaign is running, review the Search Term Report every week and add any irrelevant query you find. This ongoing process, combined with your pre-launch list, will typically reduce wasted spend by 30 to 50% within the first 60 days. The discipline required is low. The commercial impact is high. There is no other single optimisation task with a better effort-to-return ratio.

A practical starting list for most Australian service businesses includes: free, cheap, DIY, how to, tutorial, course, training, certification, guide, explained, jobs, career, salary, hiring, vacancy, template, software, tool, platform, app, review, comparison, vs, versus, alternatives, download, cheap alternatives. Start here and add industry-specific terms based on what you know about adjacent searches in your market.

Frequently Asked Questions