TL;DR
- Break-even CPA is average order value multiplied by gross margin: a 2,000 baht order at a 40% margin allows up to 800 baht of ad spend per sale (illustrative).
- Break-even ROAS is 1 divided by gross margin, so a 40% margin needs 2.5 (250%) and a 25% margin needs 4 (400%) just to cover costs.
- Maximum affordable CPC is break-even CPA times conversion rate; compare it with Keyword Planner's estimated bids before launching.
- Minimum monthly budget is target conversions divided by conversion rate, times average CPC: 30 conversions at 3% and 15 baht CPC is about 15,000 baht (illustrative).
- In Thailand, untracked LINE chats and phone calls make Google Ads look weaker than it is, so track them as conversions.
Are Google Ads worth it? They are worth it when people already search for what you sell and the profit from one sale is larger than what Google charges you to win that sale. If either condition fails, no amount of tuning will rescue the account, so the useful question is not "do Google Ads work" in general but whether the numbers work for your business, and you can check that with a calculator before you spend anything.
This guide is a decision framework rather than an explainer of what Google Ads is. It walks through the break-even math, the minimum budget that produces usable data, when Search beats social advertising and when it does not, the warning signs of an account that is leaking money, what management really costs, and how long to test before you decide. Every number below that is not a formula is labelled as illustrative, because averages copied from other industries are the fastest way to make a bad call about your own.
Do Google Ads work for small businesses?
Google Ads can work for small businesses, and in one respect the platform favours them: you pay per click, there is no minimum spend, and you can switch a campaign off the same day. A small business does not need to outspend a large one across the whole market. It needs to win a narrow set of searches where its offer is strong, such as a service area, a specialist product or a high-intent phrase that big advertisers ignore.
Where small businesses struggle is not size but thin data. A company with a large budget can afford to buy a few thousand clicks to learn what converts. A business spending a small amount each month may only see a handful of conversions, which makes it hard to tell a good keyword from a lucky one. The answer is to narrow the scope: fewer keywords, one location, one offer, and conversion tracking that is accurate from day one, so every baht produces a lesson.
Google Ads also tends to suit small businesses whose customers have an urgent or specific need. A locksmith, a dental clinic, an accounting firm or a supplier of a particular industrial part all sell to people who type what they want into a search box. A brand-new product category that nobody knows to search for is a much harder fit, which is covered further down.
How to work out a break-even CPA and ROAS before spending
The single most useful thing you can do before launching is to calculate the most you can afford to pay for one customer. That figure is your break-even cost per acquisition (CPA). Anything below it makes money; anything above it loses money, however good the click-through rate looks.
The break-even CPA formula
For a business that sells once per customer, break-even CPA equals average order value multiplied by gross margin. Gross margin here means what is left after the cost of the product or the direct cost of delivering the service, not after rent and salaries. If customers buy repeatedly, replace average order value with the gross profit a typical customer generates over the period you are willing to wait for payback.
An illustrative example: a shop with an average order of 2,000 baht and a 40% gross margin keeps 800 baht of gross profit per order. Its break-even CPA is 800 baht. If it pays more than that in ad spend to get one order, it is buying revenue at a loss.
The break-even ROAS formula
Return on ad spend (ROAS) is revenue divided by ad cost. Break-even ROAS equals one divided by gross margin. With a 40% margin, break-even ROAS is 1 / 0.40 = 2.5, often written as 250%. With a 25% margin it rises to 4, or 400%. This is why low-margin businesses find Google Ads harder: they need far more revenue per baht of spend just to stand still.
Turning break-even into a click budget
Once you know your break-even CPA, you can work backwards to the maximum cost per click you can tolerate. Maximum CPC equals break-even CPA multiplied by your expected conversion rate. Using the same illustrative shop: if 2% of visitors buy, the shop can pay up to 800 x 0.02 = 16 baht per click and still break even. Google Keyword Planner shows estimated top-of-page bid ranges for your keywords. If those estimates sit well above your maximum CPC, that is a strong early signal that the economics are tight, before a single baht has been spent.
Be honest about the conversion rate you plug in. If you have no history, test with a conservative figure and update it once real data arrives. An inflated conversion rate makes every keyword look affordable on paper.
What budget is too small to exit learning and get usable data?
A budget is too small when it cannot buy enough clicks to produce a meaningful number of conversions within a reasonable time. There is no universal baht figure, because it depends on your click prices and conversion rate, but you can calculate your own floor with two inputs.
Start from the number of conversions you want per month. Smart Bidding strategies such as Maximize Conversions or Target CPA learn from conversion data, and they make steadier decisions with a regular flow of it. A few dozen conversions a month is a common practitioner rule of thumb for automated bidding to behave predictably; treat it as a planning guide, not a Google rule. Google also describes a learning period after a new bid strategy or a significant change, during which performance can swing.
The calculation is: clicks needed = target conversions / conversion rate, then monthly budget = clicks needed x average CPC. An illustrative example: to get 30 conversions at a 3% conversion rate you need about 1,000 clicks. At an average CPC of 15 baht that is about 15,000 baht a month. If your budget is a third of that, you will get roughly a third of the conversions, which is often too few to judge.
If your realistic budget falls below your floor, you have three honest options. Narrow the campaign to fewer, higher-intent keywords so the same money buys more relevant clicks. Track a valid earlier action as well as the final sale, such as a submitted enquiry form, a phone call or a LINE chat started from the site, so there is more signal to learn from. Or use Manual CPC or Maximize Clicks with tight keyword control until there is enough conversion history for automated bidding. What does not work is spreading a small budget across many campaigns, each of which then learns nothing.
When Search beats Meta and social ads, and when it does not
The cleanest way to choose is to ask whether demand already exists. Google Search is a demand-capture channel: it shows your ad to someone who has just typed what they want. Meta, TikTok and other social platforms are mostly demand-creation channels: they put your offer in front of people who were not looking for it, based on interests and behaviour.
Search usually wins when buyers know the name of what they need, when the need is urgent or local, when the purchase is considered and people research before buying, or when the service is something people would never browse for on social media, such as legal help or equipment repair. You can check this directly: if Keyword Planner shows real search volume for the phrases your buyers use, demand exists.
Social usually wins when the product is new, impulse-driven or visual, when nobody searches for the category yet, or when you need to reach people early, before they have a problem to search for. A new snack brand or a novel gadget may find almost no search volume, while the same product can perform well in a short video ad.
Many businesses end up using both. Social builds awareness, and some of those people later search for the brand name on Google, where a cheap brand campaign catches them. The mistake is judging social ads by the same last-click conversion standard as Search, or expecting Search to sell a product nobody knows exists.
Warning signs a Google Ads account is wasting money
Wasted spend in Google Ads tends to hide in a handful of predictable places. If you already run campaigns, check these before deciding the channel does not work for you, because the problem is often the setup rather than the platform.
The search terms report is full of irrelevant queries
The search terms report shows the actual searches that triggered your ads, which can differ from the keywords you chose, especially with broad match. If you see job seekers, people looking for free versions, competitors' support pages or unrelated meanings of your keyword, you are paying for clicks that cannot convert. The fix is negative keywords and tighter match types, reviewed regularly rather than once.
Conversion tracking is missing, duplicated or counting the wrong thing
If conversions are not tracked, Google cannot optimise and you cannot judge results. Just as damaging is tracking that counts the wrong action, such as a page view of the contact page instead of a submitted form, or the same purchase counted twice by two tags. Inflated conversions make a losing account look profitable and train Smart Bidding to buy more of the wrong traffic. Check the conversion actions in Google Ads against real orders or leads in your own records for the same period.
Quality Score is consistently low
Quality Score is a 1 to 10 diagnostic shown at keyword level, built from expected click-through rate, ad relevance and landing page experience. It is not used directly in the auction, but low scores point to the same weaknesses that raise your costs: ads that do not match the search, or landing pages that do not answer it. A keyword with a score of 3 that sends people to your homepage is a common sign of a campaign that was built quickly.
Settings left on their defaults
New Search campaigns can include the Display Network and search partners by default, and location targeting can include people who show interest in your area rather than only people in it. Each of these can be right for some advertisers, but left unchecked they send budget to traffic you did not intend to buy. Review campaign settings line by line once, and again after any major change.
Agency vs in-house: what management actually costs in time
Ad spend is only part of the cost. Somebody has to build campaigns, write ads in each language you target, review search terms, add negatives, check tracking, adjust bids and budgets, test landing pages and report results. The time this takes grows with the number of campaigns, products and locations, and it never drops to zero, because search behaviour and competitors keep changing.
Running it in-house makes sense when someone on the team has the skills and can set aside regular time every week, not just when a problem appears. The hidden cost is the learning curve: mistakes made while learning are paid for in ad spend. Hiring an agency or a specialist makes sense when the time or expertise is not available internally. Agencies typically charge a flat monthly fee, a percentage of ad spend or a mix of both. Whichever model you choose, insist on owning the Google Ads account yourself and keep admin access, so the data and history stay with your business if you change provider.
A fair test of either route is whether the person managing the account can explain, in plain language, what changed last month, why, and what it did to cost per lead or ROAS.
How long to test before deciding
Test long enough to collect a meaningful number of conversions and to cover at least one full sales cycle. For a shop with same-day purchases, that might be a few weeks. For a B2B service where a lead takes a month to close, judging after ten days only tells you about clicks, not customers.
A practical structure is to split the test into phases. In the first weeks, confirm that tracking works and that the search terms are relevant. Next, look at cost per lead or cost per sale against your break-even CPA. After that, judge on lead quality or revenue, not lead count. Decide in advance what result would make you stop, scale or adjust, and write it down, so the decision is not driven by one good or bad week.
Two things shorten a test without making it less reliable: narrowing the scope so the budget concentrates on fewer keywords, and fixing tracking before launch rather than after. Two things make a test meaningless: changing the bid strategy, budget and ads all at once every few days, and judging on clicks or impressions alone.
Google Ads worth-it checklist
| Check | How to work it out | Signal that Google Ads is worth testing |
|---|---|---|
| Break-even CPA | Average order value x gross margin (or customer gross profit) | Comfortably above the cost per sale your click prices imply |
| Break-even ROAS | 1 / gross margin | A target your margins can realistically reach |
| Maximum CPC | Break-even CPA x expected conversion rate | At or above Keyword Planner's estimated bids |
| Minimum monthly budget | (Target conversions / conversion rate) x average CPC | Your budget covers it, or you can narrow scope until it does |
| Existing demand | Keyword Planner volume for buyer phrases | Real search volume for what you sell |
What this means for Thai marketers
In Thailand the break-even framework stays the same, but a few local habits change the inputs. Searches flip between Thai and English depending on the category, so a campaign that only targets one language can miss a large share of demand, and keyword research needs to cover both, including common transliterations. Mobile dominates, which makes landing page speed and a clear tap-to-call or chat button part of your conversion rate, not a design detail.
Many Thai buyers move from an ad straight into a LINE conversation instead of filling in a form. If you only track form submissions, you will undercount conversions and may wrongly conclude that Google Ads does not work. Track LINE chat clicks and phone calls as conversions, and where possible match them to closed sales offline, so your CPA reflects real customers. This is also why Relevant Audience sets up conversion tracking with GA4, enhanced conversions and offline conversion imports before campaigns scale, as described on its Google Ads management service page.
For startups, the same logic applies with a tighter budget. Relevant Audience's digital marketing for startups approach runs small, controlled campaigns in the first 30 to 45 days to gather real performance data, then moves budget towards the channels that hit the target cost per acquisition.
FAQ
Are Google Ads worth it for a small budget?
Google Ads can be worth it on a small budget if you narrow the campaign to a few high-intent keywords and one location. Work out your minimum budget with the formula above; if you cannot reach it, track an earlier action such as an enquiry or a LINE chat so the account still has enough data to learn from.
How do I know if my Google Ads are profitable?
Your Google Ads are profitable when your actual cost per acquisition is below your break-even CPA, or your ROAS is above 1 divided by your gross margin. Compare conversions in Google Ads with real orders or closed leads from your own records, because inflated tracking is a common reason accounts look profitable when they are not.
How long should I run Google Ads before judging them?
Run them until you have a meaningful number of conversions and have covered at least one full sales cycle. For quick online purchases that can be a few weeks; for considered services with long decision times, judge on lead quality over a longer period rather than on the first fortnight.
Is Google Ads better than Facebook ads?
Neither is better in general: Google Search captures demand that already exists, while Facebook and other social ads create demand among people who were not searching. If people search for what you sell, start with Search; if the product is new or visual and nobody searches for it yet, social usually fits better.
Next step
If your break-even numbers suggest Google Ads should work but your current account is not delivering, the issue is usually tracking, search terms or structure. Relevant Audience's Google Ads agency in Bangkok builds bilingual campaigns around cost per lead and ROAS, with transparent reporting and no lock-in contract. A free proposal is a low-risk way to get a second view on whether the numbers add up for your business.
