Performance Max Is Great — for Google. Here's Why It Often Fails Small Businesses

If you’ve spoken to a Google Ads rep in the last couple of years, you’ve probably heard some version of this: “Switch to Performance Max. Let Google’s AI find your customers. Just set a budget and a target.”

It sounds great. Less work, smarter targeting, more results.

For large e-commerce brands with thousands of sales a month, it often is great. For a plumber in Springwood, a physio in Penrith or a B&B in Leura, it often isn’t. Here’s why, and what we do instead.

First, whose interests does “set and forget” serve?

Let’s be fair: Google isn’t trying to waste your money. Its automation genuinely works well when it has enough data.

But it’s worth remembering how the incentives line up. Google earns money when your budget is spent. Automated campaigns are very good at spending budgets. They’re less consistent at spending them well for a small business with limited data.

An experienced account manager’s job is to make sure every dollar earns its keep. Those two goals overlap, but they’re not the same thing.

The data problem: AI needs examples to learn from

Performance Max and Google’s other AI-driven formats (automated bidding, broad match, “AI Max” features) all learn from your conversions: the calls, enquiries and sales your campaigns produce.

The more conversions, the faster and better they learn. As a rough rule of thumb, automated bidding needs a steady flow of conversions, often quoted as around 30 a month, before it stops guessing.

Now think about a typical local service business:

• 8 to 20 enquiries a month from Google Ads
• Some months busier than others (school holidays, winter in the Mountains, end of financial year)
• A handful of different services, each with its own customers

That’s not enough data for the system to learn from properly. So it spends your budget learning: trying placements, audiences and searches to see what sticks. For a small budget, that learning phase can be most of the month.

The black box: where did my money go?

Performance Max doesn’t just run search ads. One campaign can put your ads across:

• Google Search
• YouTube
• The Display Network (ads on other websites and apps)
• Gmail and Discover
• Google Maps

Google has added more reporting over time, but it’s still much harder to see exactly which searches, sites or videos your money went on than in a well-built Search campaign. And harder to stop the ones that don’t work.

For a local business, a lot of that inventory, such as banner ads in mobile games or YouTube pre-roll, rarely produces the phone calls you’re actually paying for.

Junk leads that look like success

AI optimises towards whatever you tell it counts as a conversion. If a “conversion” is any form submission, it will happily find you more form submissions. Including spam, accidental clicks and people who were never going to buy.

We regularly see accounts where Performance Max reports a great “cost per conversion”, while the business owner says the leads are rubbish. The campaign isn’t lying. It’s just optimising for the wrong thing, and it’s very good at it.

Broad match drift

The same goes for broad match keywords combined with automated bidding, which Google also pushes hard.

Broad match lets Google decide which searches are “related” to your keywords. In practice, an ad for “plumber Katoomba” can end up showing for searches like:

• plumbing apprenticeships Blue Mountains
• how to fix a leaking tap
• plumber salary NSW

Every one of those clicks costs money, and none of them is a customer. In a big account with plenty of data, the system eventually learns to avoid them. In a small account, it can keep making the same mistakes for months.

“Recommendations” that aren’t really for you

Google Ads constantly shows “recommendations” and an “optimisation score”. Some are useful. Many boil down to raise your budget, use broad match or switch to automated bidding.

Some can even be auto-applied, meaning Google changes your account without asking. We switch auto-apply off in every account we manage, and review each recommendation on its merits.

A high optimisation score means you’ve followed Google’s suggestions. It doesn’t mean your campaigns are profitable.

What works better for most small businesses

None of this means automation is evil. It means it should be earned, not switched on by default. For most small and medium businesses, we start with:

1. Tightly built Search campaigns organised around the services you actually want more of.
2. Phrase and exact match keywords, so you control which searches you pay for.
3. A solid negative keyword list, reviewed every week from the real search terms.
4. Proper conversion tracking: calls and genuine enquiries, not every page view or form spam.
5. Location targeting that matches where you’ll actually travel, not “all of Sydney”.

Then, once there’s enough real conversion data, we test automated bidding or other AI features carefully, as an experiment, against what’s already working.

When Performance Max does make sense

To be fair, there are businesses where it works well:

• E-commerce stores with a product feed and plenty of online sales each month
• Larger accounts with lots of reliable conversion data
• Businesses with strong creative, video and images, and clear goals

If that’s you, Performance Max can be a powerful tool, set up and watched properly.

Running Performance Max and not sure it’s working?

If you’re running Performance Max or broad match campaigns and can’t tell where your money is going, or the leads don’t match what the reports say, we’d be happy to take a look.

Book a free account review and we’ll show you where your budget is actually going and what we’d change. No lock-in contract, no hard sell. Just a local Google Ads specialist looking at your numbers.

Want to check your own account first? Our 9-step Google Ads audit checklist is a good place to start.