For most of its life, Performance Max asked advertisers to hand over control and trust the machine. That trade felt reasonable when budgets were small, but it stopped feeling reasonable the moment brands started pushing five and six figures a month through a campaign type with almost no visibility. Performance Max optimisation (you will see it spelled “optimization” if you search from the US, same process either side of the Atlantic) in 2026 looks different because Google has spent the last two reporting cycles adding the exact controls advertisers asked for: account-level negative keywords, first-party audience exclusions, expanded search themes and proper budget and placement reporting.
This playbook is about using those controls properly, not the basics of setting PMax up. If you need the foundational setup first, our complete Performance Max strategy guide covers asset groups, feed health and bidding from scratch.
Jump to:
- What Performance Max Optimisation Actually Means in 2026
- How Performance Max Campaigns Work Once You Add Controls
- The New 2026 Performance Max Controls, Explained
- How to Optimise Performance Max Campaigns: The Control Checklist
- Common Control Mistakes That Undo Your Optimisation
- Where to Actually Look in Your Reporting
- Frequently Asked Questions
What Performance Max Optimisation Actually Means in 2026
What is Performance Max? It is Google’s automated, omnichannel campaign type, one campaign that can serve ads across Search, Shopping, Display, YouTube, Discover, Gmail and Maps, with Google’s machine learning handling bidding, placement and creative assembly. What is a Performance Max campaign in practice for a D2C brand? It is the single campaign most Shopify and WooCommerce stores now rely on for the bulk of their Google Ads revenue.
Performance Max optimisation used to mean feeding the algorithm good inputs and hoping for the best, because there was little else you could do. That is no longer true. Google’s own product team confirmed in its 2026 Performance Max update that new steering tools now sit alongside the automation, precisely so advertisers can shape outcomes rather than just observe them. Optimisation in 2026 means using both: automation for scale, and controls for direction.
How Performance Max Campaigns Work Once You Add Controls
How do Performance Max campaigns work under the hood?
PMax takes your conversion goal, product feed, creative assets and any signals or exclusions you provide, then runs continuous auctions across every eligible channel to find the combination most likely to convert. Historically, everything you gave it was a signal, a suggestion the algorithm could ignore if it found a better opportunity elsewhere. Controls change that relationship. A negative keyword is not a suggestion, it is a hard stop. An audience exclusion is not a hint, it removes that audience from eligibility entirely. That distinction, between steering the algorithm and constraining it, is the whole point of this playbook.
The New 2026 Performance Max Controls, Explained
Google confirmed these updates directly in its Performance Max product communications for 2026, building on controls introduced through 2025. Here is what each one actually does and why it matters for a scaling D2C account. Before you layer these on, make sure the underlying campaign is built right — our guide to PMax setup and asset group structure covers the base you’re optimising on top of.
Negative keywords, now at account and campaign level
Performance Max supports negative keywords at both campaign and account level, covering Search and Shopping inventory, with the maximum keyword count expanded to 10,000 per campaign in 2025. This is the single biggest control shift PMax has had. Add your brand terms if you are running a separate brand campaign, your irrelevant category terms, and anything surfaced by the search terms report (see the reporting section below).
Search themes, expanded to 50 per asset group
Search themes tell PMax which queries to actively pursue, and the limit per asset group has been expanded from 25 to 50. More themes mean more precise direction on the search side, particularly useful for asset groups covering distinct product categories with different buyer language.
First-party audience exclusions
Google added the ability to exclude specific customer lists from a Performance Max campaign, so you can keep acquisition budget pointed at new customers rather than re-engaging people who already converted. Upload your past-purchaser list as an exclusion on prospecting PMax campaigns, and let a separate remarketing effort handle re-engagement instead.
Brand exclusions
Brand exclusion lists stop PMax from bidding on searches tied to a specific brand entity, including your own. Without this, PMax will happily spend on your branded traffic and report it as a win, even though that traffic would likely have converted for free through organic search.
Budget reporting
You can now open a budget report directly inside a Performance Max campaign to see projected end-of-month spend and how a change to daily budget is likely to affect it. Previously this took manual forecasting; now it is a native view.
Full audience reporting by age and gender
Audience reporting inside PMax now breaks performance down by age range and gender, a level of detail Search and Display have had for years but PMax lacked. It answers a simple question: is spend proportional to the age or gender groups actually converting.
Network-segmented placement reporting
Placement reporting can now be segmented by network, viewable from the “when and where ads showed” tab, giving you a clearer picture of exactly where impressions and clicks are landing across the PMax channel mix, useful for brand safety review as well as optimisation.
Want a second pair of eyes on your PMax controls?
We audit Performance Max accounts for UK D2C brands on Shopify and WooCommerce, checking every exclusion, search theme and reporting view against what your account actually needs. Book a free 30-minute PMax control audit.
How to Optimise Performance Max Campaigns: The Control Checklist
This is the practical sequence for how to optimise Performance Max campaigns once the basics from our Performance Max strategy guide are already in place.
Step 1: Build your negative keyword list before you need it
Do not wait for wasted spend to show up in reporting. Start with obvious exclusions, non-buyer intent terms like “jobs”, “free”, “how to make”, plus your own brand terms if a dedicated brand campaign already covers them. Add to the list weekly for the first two months.
Step 2: Set audience exclusions before you scale spend
Exclude your past-purchaser list from acquisition PMax campaigns from day one. This single control prevents you from paying full prospecting rates to reach people who already bought, budget that should be finding new customers instead.
Step 3: Populate search themes deliberately, not exhaustively
Fill search themes with terms that reflect real buyer language for each asset group’s specific products, not a generic list copied across every group. With the limit now at 50, there is room to be specific about product attributes, use cases and buyer intent without diluting relevance.
Step 4: Apply brand exclusions once your brand campaign is live
If you run a dedicated brand Search campaign, exclude your brand terms from PMax so the two campaigns are not competing for, and double-reporting, the same converting traffic.
Step 5: Review budget and placement reports weekly, not monthly
Budget reporting and network-segmented placement data are only useful if you actually look at them. Set a recurring weekly slot to check projected spend against target and scan for placements that do not fit your brand.
Step 6: Let Target ROAS follow performance, not ambition
Controls tell PMax where not to spend. Bidding still tells it how hard to chase a result. Set an initial Target ROAS 20 to 30 percent below your current actual ROAS, then raise it gradually as performance stabilises, rather than setting the number you wish were true.
Common Control Mistakes That Undo Your Optimisation
Adding every control on day one
Negative keywords, audience exclusions and tight search themes all constrain the algorithm’s search space. Layer them in gradually on a new campaign so you can attribute performance changes to a specific control, rather than resetting the entire learning phase at once.
Excluding audiences without a plan for them
If you exclude past purchasers from PMax, make sure a remarketing or retention flow is actually reaching them elsewhere. An exclusion with nowhere for that audience to go is a missed sale, not a saving.
Treating search themes as a keyword list
Search themes are direction for the algorithm, not exact-match keywords. Overloading them with every conceivable variant does not sharpen targeting the way negative keywords do, it just adds noise.
Ignoring the reports because PMax “just works”
Budget and placement reporting exist because PMax used to hide this information. Not checking them because performance looks fine on the surface means you will not catch a placement or spend pattern problem until it has already cost you.
Where to Actually Look in Your Reporting
Four views matter most for ongoing Performance Max optimisation: the search terms report (to feed your negative keyword list), the budget report (to catch pacing issues before month end), the audience report with age and gender detail (to check spend matches your actual buyers), and the network-segmented placement report under “when and where ads showed” (to confirm brand safety across channels). Review all four on a weekly cadence rather than waiting for a monthly account review to surface problems that were visible for weeks.
For the bidding side of PMax optimisation, our Google Ads ROAS guide for ecommerce covers how to set and raise Target ROAS without throttling spend, and sits alongside this playbook as the other half of getting PMax right.
Conclusion: Optimisation Is Now a Two-Sided Job
Performance Max optimisation in 2026 is no longer just about feeding the algorithm clean data and waiting. Google has given advertisers genuine controls, negative keywords at scale, audience exclusions, expanded search themes, and reporting that finally shows where budget goes. The brands that pull ahead will be the ones that use both sides of PMax deliberately: automation for reach, controls for direction. Skip the controls and you are back to hoping. Use them properly and Performance Max becomes a campaign you can actually manage.
Get a free Performance Max control audit from Engage Positive.
We will review your negative keyword lists, audience exclusions, search themes and reporting setup, and hand you a written action plan. No obligation, no sales pitch. Request your free PMax audit.
Frequently Asked Questions
Performance Max optimisation is the ongoing process of steering and constraining Google’s automated PMax campaigns, using negative keywords, audience exclusions, search themes and Target ROAS, rather than simply launching the campaign and leaving the algorithm to run unchecked.
Use account- and campaign-level negative keywords to block irrelevant queries, exclude past purchasers or other unwanted audiences from acquisition campaigns, and apply brand exclusion lists so PMax cannot bid on your own branded traffic.
Yes. Performance Max supports negative keywords at both account and campaign level, covering Search and Shopping inventory, with a limit of up to 10,000 keywords per campaign following the 2025 expansion from the previous limit of 100.
Up to 50 search themes per asset group, expanded from the previous limit of 25. Use them to describe real buyer language for that specific group’s products rather than duplicating the same generic list across every asset group.
Partially. Channel and placement reporting, including network-segmented data under “when and where ads showed”, shows where ads served, and budget reporting shows spend pacing. Full search term visibility is still more limited than in a standard Search campaign.
Upload your customer list to Google Ads and apply it as a first-party audience exclusion on your acquisition Performance Max campaigns. This keeps prospecting budget focused on new customers, while a separate remarketing campaign handles existing customers.
