Performance Max campaign structure: one campaign or several?

Performance Max now decides where a big share of many Google Ads budgets goes: which searches, which channels, which products. The main thing it still leaves to you is how your campaigns are split, and what goes in each one. In a lot of businesses, that decision is made once, at set-up, by someone running Google Ads alongside a dozen other jobs, and it’s rarely looked at again. Here’s how to tell whether your structure is helping or holding you back, and what to ask the person running it.

The decision Performance Max leaves to you

Performance Max is Google’s all-in-one campaign type. A single campaign can run ads across Search, YouTube, Display, Discover, Gmail and Maps, plus Shopping ads if you sell products, and Google’s AI decides where each pound goes. According to Google, more than a million advertisers use it.

That’s the appeal, but it changes where the important decisions sit. Inside a campaign, you can’t tell Google to put 30% of the budget on YouTube or hold some back for a new product line. For each campaign, you set a budget, a goal, and, if you use one, a target cost per acquisition (CPA) or return on ad spend (ROAS). So deciding which products, services or regions share a campaign is really deciding which ones share a budget and a target.

Google’s own advice leans towards fewer campaigns. Its guidance for retailers says a new Performance Max campaign should be “as simple as possible”, because “Google AI works best when it can make your ads better across all places using a unified budget”. It also accepts that you’ll sometimes need more than one: for different countries or languages, for different budgets or ROAS targets, or at busy times to separate seasonal products, high-margin products and everything else.

Every split shares out the same data

Performance Max uses Smart Bidding, which learns from your conversions: sales, leads, calls. Each campaign learns from its own. Split one campaign into four, and you don’t get four times the learning. You get the same conversions shared four ways, and each campaign has less to go on.

Google gives two useful markers. When you set a target CPA, it suggests basing it on the last 30 days of results, “including at least 30 conversions”. For value-based bidding on leads, it suggests a conversion goal with “at least 15 conversions in the last 30 days”. Neither is a hard minimum, but both are a fair guide to when a campaign has enough data to work with.

Splits are rarely even, either. In many accounts, a few bestsellers or one service line drive most conversions. Give everything else its own campaign, and those campaigns can sit for months without enough data, while someone keeps adjusting them.

The opposite mistake is just as common. Put everything in one campaign with one target, and Google will do what it’s asked: find the cheapest conversions. That often means bestsellers, your own brand name and people who were going to buy anyway, while new lines and higher-margin products barely get a look in.

Signs your structure needs a look

You don’t need to log in to Google Ads to spot most of these. They show up in the numbers you already get, and in the questions nobody can quite answer.

Four questions before you add or keep a campaign

Use these when someone proposes a new campaign, and to decide whether each existing one still earns its place. The first two ask whether there’s a reason to split. The second two ask whether you can support it.

Failing the test doesn’t mean ignoring the difference. It means handling it inside a campaign rather than with a new one. Google suggests using several asset groups within one campaign for different product sets, themes, or customer groups, for example.

Common splits, and the lighter option to try first

Most Performance Max structures are split in one or more of these ways. Each can earn its place, and most have a setting that may do the job without a new campaign.

What Google has added since 2025

Until recently, the only way to see or steer some things in Performance Max was to split it up. That’s changed. If your structure was set up before 2025, some splits may now be doing a job a setting does better. Some of the blind spots that made people nervous of Performance Max have gone, too.

Why this slips when Google Ads is one job among many

None of this is beyond a capable marketer. The problem is time. Performance Max needs a steady rhythm of checks, and when Google Ads is one job among many, the urgent checks get done, and the structural ones wait. Recent research suggests that’s the norm, not the exception.

A healthy rhythm for Performance Max looks something like this.

When time is short, the weekly checks happen, the monthly ones happen when they can, and the quarterly review quietly drops off. That’s how an account ends up with a structure built around last year’s range, last year’s margins and last year’s budget, without anyone doing anything wrong.

How we can help, without taking over

Outside help doesn’t have to mean replacing the person who runs your Google Ads. Often the most useful thing is a second pair of eyes and some extra hands, so they can get to the work that keeps slipping. We work as an extension of in-house teams, and that can look like any of these.

1. A structure review.We look at how your Performance Max campaigns are split, put each one through the four questions, and show you what we’d merge, split or leave alone.
2. A one-off reset.We make the changes alongside your team and give each campaign time to settle before anyone judges it.
3. Ongoing support.Weekly checks, monthly reporting your team can actually use, and a quarterly structure review that happens.
4. Full management.If Google Ads is better off your team’s plate altogether, we run it with brand exclusions, negative keyword lists and location controls in place from day one.

Frequently asked questions