The Importance of Keyword Research in SEM

Every paid search campaign is built on a list of words. Choose them well and your ads appear in front of people who are ready to call, book or buy. Choose them badly and you pay for clicks from students researching homework, job seekers, bargain hunters and people looking for a different service altogether. In a small, competitive market like Singapore, where clicks in sectors such as renovation, legal and education can be costly, that difference shows up quickly in your budget.

This guide explains the importance of keyword research in SEM from the ground up. We start with how keyword advertising actually works, then cover search intent, match types, how to find and judge keywords, how to organise them into campaigns and how to keep refining them once ads are live. You will finish with a step-by-step plan you can apply to your own Google Ads account.

What is keyword advertising and how does it work?

Keyword advertising is a form of search engine marketing (SEM) in which you pay to show text ads when people search for particular words or phrases. On Google Ads, for example, you choose keywords that describe what you sell, write ads, set a budget and decide how much you are willing to pay. You are usually charged when someone clicks, which is why it is often called pay-per-click (PPC). Our guide to the types of search engine marketing places this within the wider SEM picture.

When someone searches, Google runs a quick auction among the advertisers whose keywords match that search. Your keyword does not have to be identical to the search; Google decides whether a search matches based on your keyword’s match type, which we cover below. The auction then weighs several factors, including your bid, the quality of your ad and landing page, and the context of the search, to decide whether your ad shows and in what position.

This is why keyword choice matters so much. Your keywords determine which auctions you enter, and therefore which people see your ads. They also influence ad quality: Google’s Quality Score help page describes three components, expected click-through rate, ad relevance and landing page experience, and ad relevance is essentially how closely your ad matches the intent behind the keyword. We explain this diagnostic in more depth in our guide to Quality Score, and the bidding side in how PPC bidding works.

Why keyword research is important in SEM

Keyword research is the work of finding the search terms your customers use, judging which ones are worth paying for, and organising them so each ad and landing page fits the search. In SEM it does four jobs at once.

It decides who sees your ads

A keyword is effectively a targeting instruction. “Office cleaning” and “office cleaning jobs” look similar, but the second attracts people looking for work, not buyers. Research helps you include the first and exclude the second before you spend a dollar.

It protects your budget

Small budgets are spent fastest on broad, vague terms. Research lets you concentrate spend on specific, high-intent phrases and set aside the expensive generic terms until you have data showing they convert.

It shapes your ads and landing pages

Once you know the exact problems people describe, you can write ads that echo their language and build landing pages that answer the question they asked. That alignment improves the user experience and tends to support ad quality.

It reveals how your market thinks

Search data shows the words customers really use, which often differ from industry jargon. A dental clinic might say “dental implant”; patients may search “replace missing tooth” or “implant price Singapore”. These insights also feed your SEO and content; see how PPC and SEO work together.

Search intent: the filter that matters most

Before looking at volumes or costs, sort every keyword by what the searcher is likely trying to do. The table below is a practical way to do that, with illustrative examples for a Singapore aircon servicing company.

In our experience, most early waste in small accounts comes from informational and irrelevant searches slipping through. Long, specific phrases tend to carry clearer intent than short ones; our comparison of long-tail and short-tail keywords explains the trade-off between reach and precision.

Keyword match types and how they change your reach

Match types control how closely a search must relate to your keyword before your ad can show. Google’s help article on keyword matching options describes three:

• Broad match (the default, written without symbols): ads may show on searches related to your keyword, including ones that do not contain its words. It gives the widest reach and relies heavily on Google’s understanding of intent and your account’s signals.
• Phrase match (written in quotation marks, such as “aircon chemical wash”): ads may show on searches that include the meaning of your keyword.
• Exact match (written in square brackets, such as [aircon chemical wash]): ads may show on searches with the same meaning or intent as your keyword.

Note that even exact match today covers close variants and same-meaning searches, not only the literal string. Google’s definitions have changed over the years, so check the live help page rather than relying on older guides.

A cautious starting point for a small budget is to use phrase and exact match for your core high-intent terms, review the searches that trigger them, and then test broad match once you have reliable conversion tracking and a smart bidding strategy in place. Whatever you choose, pair it with a solid negative keyword list; our guide to negative keywords in PPC shows how.

Where to find keyword ideas

Good keyword lists combine tool data with real customer language. Useful sources include:

• Google Keyword Planner. Free inside Google Ads. Google’s Keyword Planner guide describes two starting points: discovering new keywords from a word or website, or getting search volume and forecasts for a list you already have. Volumes are often shown as ranges, and very low-volume or sensitive terms may not appear, so treat the numbers as directional.
• Your search terms report. Once ads run, the search terms report shows the actual searches that triggered your ads. This is the most reliable source of new keywords and negatives.
• Google Search Console. If you already have organic traffic, the queries report shows the phrases people use to find your site.
• Customer conversations. WhatsApp messages, enquiry forms and call notes contain the exact phrasing, including Singlish, abbreviations and Chinese or Malay terms, that tools may miss.
• Google’s own search page. Autocomplete suggestions and related searches show how people extend a phrase.

How to judge whether a keyword is worth paying for

Not every relevant keyword deserves budget. For each candidate, ask:

1. Is the intent commercial? Would someone typing this plausibly become a customer soon?
2. Do we offer exactly this? If the search is for a service you do not provide, or an area you do not cover, skip it.
3. What might a click cost? Keyword Planner gives indicative bid ranges. Compare them with what a customer is worth to you; our guide to cost per click explains the maths.
4. Is there enough volume to learn from? A highly specific phrase with almost no searches will not spend budget, but it will not teach you much either.
5. Do we have a page that answers it? If not, either build one or leave the keyword out for now.

As a rough planning approach, work backwards from the number of enquiries you need and an estimated conversion rate to see how many clicks you can afford. These are estimates, not forecasts, and should be revised once real data arrives. Our PPC budget guide walks through the calculation.

A step-by-step keyword research plan for your next campaign

The plan below suits a small team launching or rebuilding a Google Ads search campaign. Timings are illustrative.

1. Day 1 – Define offers and locations (owner: business owner). List the services you want enquiries for, the areas you serve and the customer value of each. This is your keyword boundary.
2. Day 1–2 – Collect seed terms (owner: marketing lead with sales staff). Gather ten to twenty phrases from customer messages, call notes and staff knowledge, including local terms and other languages your customers use.
3. Day 2–3 – Expand with Keyword Planner (owner: marketing lead). Enter seed terms and your website, filter to Singapore, and export ideas with volume ranges and bid estimates.
4. Day 3 – Sort by intent (owner: marketing lead). Tag each idea as transactional, commercial, informational, navigational or irrelevant. Keep the first two; move irrelevant terms to a negative list.
5. Day 4 – Group into tight themes (owner: marketing lead). Create ad groups of closely related keywords, each with a matching landing page. “Aircon chemical wash” and “aircon gas top-up” belong in different groups.
6. Day 4–5 – Choose match types and negatives (owner: marketing lead). Start core terms on phrase or exact match, add your negative list, and confirm conversion tracking for calls, forms and WhatsApp clicks.
7. Day 5 – Write ads to match each group (owner: copywriter). Reflect the keyword theme in headlines and send traffic to the most relevant page. Tools such as dynamic keyword insertion can help but need careful testing.
8. Weeks 2–4 – Review search terms weekly (owner: marketing lead). Add converting searches as keywords, add irrelevant ones as negatives and pause terms that spend without results.
9. Month 2 onwards – Expand carefully (owner: marketing lead and business owner). Test broader match types or new themes only when the core campaign is producing enquiries at an acceptable cost.

How AI can help with SEM keyword research, and its limits

AI tools are useful for the slow parts of keyword work: brainstorming variations, translating customer phrasing into keyword themes, grouping long lists by intent, spotting patterns in a search terms report and drafting ad copy for each group. Google Ads itself uses machine learning in broad match and automated bidding, so some of the matching is already automated.

The limits matter. General AI chat tools do not have access to Google’s search volume data and may invent figures if asked, so always take volume and cost from Keyword Planner or your own account. AI may also misjudge local nuance, such as which estate names customers actually use or whether a Singlish phrase signals buying intent. Keep a person responsible for which keywords go live and how much is spent.

Marketing2u’s AI Ads Agent follows that principle. It analyses search terms, flags wasted spend and suggests negatives and keyword ideas from a read-only connection to Google Ads, with metrics calculated from real account data rather than estimates, and it does not change your ad account itself. Like any tool, it cannot promise a particular cost per lead.

Common keyword research mistakes in SEM

• Bidding on one-word generic terms. “Lawyer” or “tuition” is expensive and vague. Specific phrases are easier to convert.
• Mixing unrelated keywords in one ad group. The ad cannot be relevant to all of them, and the landing page will fit none well.
• Ignoring the search terms report. Your keyword list is only a starting point; actual searches tell you what you are paying for.
• Treating Keyword Planner volumes as exact. They are ranges and estimates, useful for comparison rather than precise forecasting.
• Forgetting local language and geography. Customers may search by estate, MRT station or in Chinese; tools may under-report these.
• Bidding on competitor brand names without thought. Google’s trademark policy lets trademark owners ask for their marks to be restricted in ad text, and these clicks often convert poorly because the searcher wanted someone else.
• Never revisiting the list. Seasonal demand around Chinese New Year, school holidays or the year-end shift what people search for.

The takeaway on keyword research in SEM

Keyword research in SEM is not a one-off task done before launch. It is the ongoing discipline that decides which auctions you enter, who sees your ads, how relevant they are and how far your budget stretches. Start with intent, keep ad groups tight, use match types deliberately and let the search terms report guide every refinement.

If you are setting up measurement alongside your campaign, our list of SEM KPIs to track shows which numbers tell you whether your keywords are working.

Frequently asked questions

What is the difference between SEO and SEM keyword research?

Both start with understanding what customers search for. SEM keyword research focuses on terms worth paying for right now, so commercial intent, cost per click and conversion matter most. SEO keyword research often includes informational topics that build visibility over time, which can then feed your content plan.

How many keywords should an ad group have?

There is no fixed rule, but keep each ad group to a tight theme so one ad and one landing page can match every keyword in it. For many small accounts that means a handful to a couple of dozen closely related keywords. If you find yourself writing ads that cannot mention the keyword theme, split the group.

Is Google Keyword Planner free?

Yes, Keyword Planner is available free inside a Google Ads account. Search volumes are often shown as ranges, and forecasts are estimates based on recent data, so use them to compare options rather than as precise predictions. Your own search terms report becomes more reliable once ads are running.

Which match type should a small business start with?

Many small advertisers start core high-intent keywords on phrase or exact match, which gives more control while they learn which searches convert. Broad match can work well once conversion tracking is reliable and smart bidding has data. Whichever you use, review the search terms report and maintain negative keywords.

Sources and further reading

• Google Ads Help: About keyword matching options
• Google Ads Help: Use Keyword Planner
• Google Ads Help: About Quality Score
• Google Ads Help: About the search terms report

Related guides

• What Is Keyword Research: Your SEO Starting Guide
• Negative Keywords in PPC: The 3 Match Types and How to Use Them
• What Is Ad Quality Score in Google Ads and How to Improve It
• Long Tail Vs Short Tail Keywords: Understanding The Difference
• 7 Steps To Determine PPC Budget: A Practical Guide For Advertisers

Browse every article in our Paid Advertising guides.