Most articles answering this question give you a list of industries. Lawyers. Plumbers. Dentists. E-commerce.
That list isn't wrong. But it skips the part that actually determines whether Google Ads will make you money.
We sat down with Patrick McKeering, Paid Ads Specialist at Websites That Sell, to get past the industry list and into the business decisions that actually matter.
Start Here: Is Anyone Searching for You?
Before anything else, Patrick's first question to any business owner asking about Google Ads is the same.
"The first thing that would come to mind would be: is there existing demand for your product or service? Are people going to Google and searching for what you do?"
For established service categories, this is obvious. People know what a plumber is. When a pipe bursts, they know what to type. The same goes for lawyers, accountants, dentists, electricians, and mortgage brokers. The demand is there, and it isn't going anywhere.
But not every business has that foundation, and Patrick has seen it catch people out.
"We had this guy come to us, and he had this spray for plants. An all-in-one organic spray, some secret formula he'd bought the patent for. It made your plants blossom, your fruits grow bigger. But no one actually knew about that product. There wasn't an actual core name for it. There wasn't existing demand for it."
The problem wasn't the product. Nobody knew how to search for it.
"Everyone knows that if I have an electrical problem, I call an electrician. But not everyone knows that, hey, instead of having bananas this size, I could actually have bananas this size. They don't even know it exists."
You can't capture intent that doesn't exist. For a business like that, Google Ads is the wrong starting point. You need to create demand first through Meta campaigns, through content, through education. Many SaaS products fall into the same trap. So does anything that requires a customer to understand a problem before they'll search for a solution.
Patrick's suggested first step costs nothing. "Go to Google Keyword Planner. Sign up for a Google Ads account, jump in, and just see if there's any demand for your business. And then you can have a look at what it's going to cost you with your cost per click."
Twenty minutes of that research will tell you more than most advice.
Industries That Google Ads Consistently Work For
Once demand is confirmed, some categories stand out.
"Your service-based businesses; your electricians, your plumbers, lawyers, your dentists. Businesses where you have that ability to increase the lifetime value of your customers."
Patrick points to emergency and need-driven services in particular. When someone's hot water system dies at 7 pm or a tooth cracks on a Friday, they've already decided to buy; they don’t have a choice. They just need to find someone. Google Ads puts you in front of that person at the exact moment they're ready.
"Your dentists, your plumbers, your electricians, where it's I need this problem solved now. They would be really good for Google Ads."
Ecommerce works too, but with a condition. "If you've got a niche that has demand but it's not super competitive, your cost per click is going to be lower, demand for your business is going to be a lot higher because there's not a lot of competitors out there."
Broad, competitive categories are a different story. "Clothing. It's highly competitive, and it's going to be very difficult to differentiate your unique selling proposition just through Google Ads alone."
The Test Most Business Owners Skip
Even in a good-fit industry, the economics of the individual business determine whether ads will actually be profitable.
"If you're a sole trader, a tradie, just starting up without the backend processes to upsell — say you're a plumber and you come in to fix a leaking tap. If you don't have a process to do a plumbing check on the whole house, then yeah — because Google Ads is so competitive and the cost per click is super high, you're not going to be able to maximise the value of that job."
Cost per click in competitive trades can run $20–$35. If the job is worth $150 and there's nothing else to sell, the maths doesn't work.
"You can buy new customers, but if you don't have the backend, they might not be profitable for you."
The businesses making Google Ads work in high-CPC industries are the ones with systems that expand the value of each customer. The plumber who does a whole-house check while on-site. The electrician who turns a $150 job into a $400 job. The dentist who books the next two appointments before the patient leaves.
Ecommerce is the same. "A lot of the time on the front end, we're just breaking even. So it's just an acquisition channel. The profit really comes from repeat sales, from the upsell, or from generating a higher average sale value. It comes from operating the systems — marketing to your list, doing promotions."
Patrick's framework for working this out before you start: "It may cost you $200 on the front end to acquire a customer. On your first sale, that may be break-even. But say that customer comes back three times a year and your average job value is $200 — that initial $200 cost has just made you $400. You're investing to make that $400."
Know those numbers before you commit budget. If you can't answer what a customer is worth over their lifetime, you're guessing, and paid advertising punishes guessing fast.
Great Ads Can't Fix a Bad Website
A business can have strong demand, the right industry, and solid unit economics and still waste money on Google Ads. As David Krauter, founder of Websites That Sell, puts it: "Great ads can't fix a bad website."
Patrick sees it constantly.
"The difference between Google Ads working and not working could be as little as having a phone number and an enquiry form on your website. We get so many sites still today — they're a local business, they don't have their phone number displayed, they don't have an enquiry form."
He's not being abstract. "The phone number's down at the bottom in 12-point font, white on white." It just doesn’t work. The traffic arrives. It leaks straight out.
"If you weren't reporting on conversions, you'd be saying this is working like magic — look at all these clicks from qualified people. The problem is they're not converting. So in the business owner's mind, they're like, this isn't working. I'm not making any money. But it could be as simple as fixing that."
In e-commerce, the gap is more visible. "If you're in a very competitive industry and your competitors have a super flashy website with very high quality lifestyle photography, environmental shots, lots of reviews — and you're coming in with a website that looks like it was built in '94 — it's just not going to happen."
The other non-negotiable is conversion tracking. "Conversion tracking is tracking the result you're getting from your ads inside the ad account, whether that's phone calls, sales in your store, or a form submission requesting a quote. Not tracking those is a surefire way to not only not know what's happening, but also not give Google the data it needs to learn."
Google's algorithm needs around 30 conversions within a 30-day window to optimise effectively. Without that data, you're not just operating blind; you're preventing the system from doing its job.
Patrick says this is usually the point where business owners realise they need help. "You're already spending a couple of thousand dollars a month. You know it's working, but you don't know exactly what's working. You don't know where the money's leaking. You don't know if you're actually losing money because it's not optimised properly."
That's the sign. "Let's sit down. Let's get tracking in place. Let's work out how much of this comes from your ads and how much comes from organic. Then we can work out — this ad group's working, this one isn't. Turn off the losers, scale the winners."
Google Ads vs SEO vs Meta ADS
Patrick is direct about when each channel makes sense.
"With Google Ads, it buys you speed. For a business that needs to get off the ground quickly — if you've got the search demand there, you're a service-based business, and you need leads today — you can get a campaign set up and have the phone ringing that very afternoon."
SEO takes three to six months to build momentum and twelve or more to reach its ceiling, which usually leads to a wider focus and more opportunities. "If you need to make sales from day one and you haven't got twelve months to invest in SEO, Google Ads is the route."
But speed costs money, and some business models can't support it. "For tow trucks — that's the ceiling. You can't upsell them two tows. They're broken down once, they don't want to pay twice. If the click cost doesn't make sense, Google Ads is probably not the right thing. Let's do an SEO campaign and stick you up there without having to keep paying per click."
For businesses that need to educate before they can sell, Meta is often the right first move. "If people don't know about your product, or it's something you need to educate around first, that's your Meta ads or SEO. If you need to get to market quickly and the demand's there, Google Ads all day long."
And SEO doesn't compete with Google Ads; it makes it more profitable. "If you've got good SEO in place, it actually makes your ads more profitable because it gets your brand in front of people before they search for the actual thing they want to buy."
Brand traffic is also dramatically cheaper to capture than generic high-intent terms. A lawyer paying $150 per click on "lawyer [city]" might pay fifty cents when someone searches their firm name directly. "Your competitors are bidding on your brand terms. If you turn off a brand campaign, those conversions just disappear. The rug gets pulled out from underneath your feet."
How to Budget and Scale Your Ads
On budget, Patrick starts with how the algorithm actually learns, not an arbitrary number.
"There's no one-size-fits-all. You want to look at the average cost per click for your industry, work out how many clicks that gets you, then apply your industry's average conversion rate to figure out how many leads that budget will actually generate."
As a rough baseline across the accounts he manages: "I would recommend minimum $50 to $100 a day. Looking across all our clients, where they started would be around $50 a day — that's $1,500 a month. From there you can scale."
But scaling isn't linear. "Google's AI needs 30 conversions within a 30-day window to optimise, to learn, to understand where your leads are coming from."
Once past that threshold, check your search impression share, confirm the cost per conversion is still sustainable, and increase spend in 20% increments.
"Google Ads running $1,500 a month isn't the same as running $10,000 a month. You don't just say this is working at $1,500 — let's throw $10,000 at it. It's a process of adjusting the dials and keeping it at a profitable level."
TLDR; Where to Start Right Now
Patrick's one rule for any business owner trying to decide: "Go to Google Keyword Planner. See if there's any demand for your business. See what it's going to cost you per click. Then you can start making decisions."
Demand, unit economics, a website that converts. Get those three right and the industry almost takes care of itself. Miss one and the industry won't save you.
If you want to run the numbers for your specific situation, get in touch — it's a quick conversation to work out whether this channel makes sense for you.