Key takeaways
- Run Performance Max well in 2026: get conversion tracking right first, build Excellent-strength asset groups, and make PMax work for lead gen, not just retail.
- Feed Performance Max accurate conversion data with real values, strong and varied creative, and clear audience signals, then leave the learning phase alone for four to six weeks before you judge it.
- In the UK a meaningful share of PMax conversions are modelled rather than directly observed, so wire in Consent Mode v2 and treat headline numbers as directional, not exact.
- Consolidate into fewer, well-fed campaigns instead of over-segmenting, run PMax alongside a lean Search campaign, and import qualified-lead data from your CRM for lead generation.
What Performance Max is, and how it actually works
Performance Max is one campaign that runs across all of Google’s inventory at once, with the machine deciding where, when and to whom your ads show. Instead of separate Search, Shopping, Display and YouTube campaigns, you give it a goal, a budget, some creative and a few signals, and Smart Bidding does the rest.
The building blocks:
- A conversion goal: the outcome you bid towards (a purchase, a lead, a booked call). It is the most important input, which is why half this article is about tracking.
- Asset groups: themed bundles of headlines, descriptions, images, logos and videos, plus optional audience signals and search themes.
- A product feed, for retail: e-commerce accounts connect a Google Merchant Center feed, and PMax then behaves like Shopping with extra reach.
- Smart Bidding: Maximise conversions or Maximise conversion value, usually with a target CPA or ROAS.
The trade is control for reach: the whole of Google from one campaign, minus the keyword-level steering of a classic Search campaign.
What changed for Performance Max in 2026
The theme for 2026 is transparency and control, walking back the “black box” criticism PMax earned early. The changes worth knowing:
- Channel-level reporting. A channel performance view breaks results down by Search, Shopping, YouTube, Display, Discover, Gmail, Search Partners and Maps, with clicks, conversions and cost you can download (Google, Channel performance and more reporting coming to Performance Max). You could not see this before.
- Full search terms reporting. PMax now surfaces the terms driving its traffic at a level close to standard campaigns, so you can act on what people typed.
- Campaign-level negative keywords, for everyone. Once request-only, now available across accounts with a much higher ceiling, so you can block irrelevant and brand-damaging queries directly.
- Brand exclusions. A dedicated control that stops PMax serving on your own brand searches, essential for reading performance honestly.
- Search themes. Up to 25 per asset group to point PMax at query clusters it might miss, though Google keeps lifting these limits, so check your account.
- AI Max interplay. AI Max is not a replacement for PMax but a set of AI features layered onto standard Search campaigns (query expansion, creative variation, smarter URLs). Google leans towards running both, AI Max for high-intent Search and PMax for broad reach, so set them up deliberately to avoid the layers fighting.
Is Performance Max right for you? E-commerce, lead gen, and when Search still wins
Performance Max suits accounts with solid conversion data and something real to optimise towards: a product feed with healthy margins, or a lead-to-sale signal that tells Google which enquiries are worth money. It is strongest for e-commerce and genuinely usable for lead generation once your tracking is mature. It is weakest when your conversion data is thin or not yet tied to business value.
Search still earns its own campaign when:
- You need tight control over exact queries: regulated sectors, sensitive terms, or a small set of high-value keywords.
- Your conversion volume is very low, so Smart Bidding has little to learn from.
- You are protecting cheap, high-converting brand terms.
For most UK SMEs it is not PMax instead of Search, but PMax plus a lean Search campaign, each doing what it is good at. If you would rather have this scoped and run for you, that is what our paid media and Google Ads management covers.
Get your conversion tracking right first
This part decides everything else: Performance Max optimises towards the conversions you give it, so if that data is wrong or double-counted, PMax pours budget into the wrong places while the reports look fine. Google is blunt about it, opening its lead-gen guidance with the need for a solid measurement and data foundation (Google Ads Help, Performance Max best practices for lead generation).
Before you launch:
- One clean conversion setup, not three. A GA4 import, a Google Ads tag and a hardcoded snippet all firing at once inflate conversions and mislead bidding. One source of truth per action.
- Real values, not flat ones. A lead worth £5,000 and one worth £50 should not both count as “1”. Value-based bidding needs real values.
- Enhanced Conversions on. Hashed first-party data recovers conversions that would otherwise go unseen.
- The right goal. For lead gen, bid towards the action closest to revenue you can measure, ideally a qualified lead, not a raw form fill.
If your tracking is not watertight, stop and set your conversion tracking up properly before spending another pound on PMax.
The UK reality: Consent Mode v2 and modelled conversions
Here is the honest bit most agencies skip. In the UK, a meaningful share of your Performance Max conversions are modelled, not directly observed, because of consent. Under PECR you must get consent before setting non-essential cookies, and Google requires Consent Mode v2 for UK and EEA traffic, so every visitor who declines is not tracked in the usual way (Google, EU user consent policy).
- Some reported conversions are estimates. With Consent Mode wired in, Google models the conversions it cannot see from non-consenting users, so treat headline numbers as directional, not exact.
- Broken consent wiring quietly destroys data. If the banner shows but the signal never reaches Google, modelling does not kick in and PMax loses conversions silently.
- The legal picture is real. The ICO’s guidance on storage and access technologies sets out what valid consent looks like, and analytics and advertising cookies sit inside it (ICO, Guidance on the use of storage and access technologies).
Get your conversion tracking and GA4 set-up and Consent Mode checked, then read PMax reporting knowing part of it is modelled. An agency that treats every UK conversion as hard fact is not paying attention.
Structure your account without starving the algorithm
Fewer, better-fed campaigns almost always beat lots of thin ones, because Smart Bidding needs a healthy flow of conversions to learn, and splitting a campaign into five starves each one. Segmenting by product, location or audience feels tidy, but usually backfires.
A composite example (illustrative, not a specific client): a business splits budget across eight tightly themed campaigns, each on a small daily budget, so none gathers enough conversions to exit learning and cost per lead sits far too high. Consolidate into two or three sensibly grouped campaigns, each fed enough to learn, and performance usually settles within weeks.
So start with one PMax campaign unless you have a clear reason to split (different margins, goals or budgets). Split by economics, not neatness: a different target ROAS or goal is a real reason, “feels more organised” is not. And never make a split that starves a campaign of the conversions it needs to learn.
Build asset groups that reach “Excellent” strength
Fill each asset group with the full range of creative Google allows: more strong, varied assets mean more combinations to test and a better shot at “Excellent” Ad Strength. Per Google’s specs, that is up to 15 headlines, 5 long headlines, 5 descriptions, 20 images, 5 logos and 5 videos per group (Google Ads Help, Performance Max campaigns specs and format requirements).
- Headlines (up to 15): mix benefits, offers, features and a call to action, and vary the length. Not 15 versions of one sentence.
- Long headlines and descriptions (up to 5 each): real detail, what you do, where, why you, the next step.
- Images (up to 20) and logos (up to 5): cover landscape, square and portrait ratios. Missing ratios means missing placements.
- Video (up to 5): add your own, even a simple one. Leave it blank and Google auto-generates one, which a basic custom video usually beats.
“Poor” and “Average” groups limit where PMax can serve, so push each towards “Good” or “Excellent” (Google Ads Help, Best practices for asset groups in Performance Max campaigns). One theme per group keeps creative coherent.
Use audience signals as hints, not targeting
Audience signals tell Performance Max where to start looking, they do not fence it in. You describe who you think converts (customer lists, high-intent or in-market segments), and PMax uses that as a hint before branching out to similar people. So feed it your best first-party data, with a customer match list of actual buyers the strongest signal you can give. Do not expect it to restrict targeting, though: if you need PMax to show only to a narrow group, it is the wrong tool. Signals steer, they do not lock.
Search themes, cannibalisation and brand safety
Search themes point PMax at query clusters you know matter; brand exclusions stop it eating traffic that belongs to your Search campaigns. Used together they keep PMax honest on Search and protect your brand.
The risk is cannibalisation: unchecked, PMax serves on your brand terms and claims credit for conversions that would have happened anyway. To keep the picture clean, turn on brand exclusions and let a dedicated Search campaign own that cheap brand traffic, add campaign-level negative keywords for irrelevant or off-brand searches (open to everyone now), and use the search terms report to cut the rubbish, feed winners back into your headlines and search themes, and set placement and content exclusions for brand safety.
Budget, bidding and the learning phase
Set a value-based bid strategy, give the campaign enough daily budget to gather conversions quickly, then hold your nerve for four to six weeks while it learns. The most expensive mistake in PMax is impatience: resetting the learning phase every time you change something.
- Bid strategy. Maximise conversions (with a target CPA) for lead gen, or Maximise conversion value (with a target ROAS) for retail. Start targets loose so you do not choke impressions, then tighten as data builds.
- Budget. No official UK minimum, but Smart Bidding needs volume. As a rough floor, aim for 20 to 30 conversions a month per campaign, which for many UK SMEs means roughly £30 to £50 a day to start, more for competitive retail.
- Learning phase. One to two weeks minimum, up to six for lower-volume setups. Avoid big changes to budget, goals, bids or assets; small creative additions are fine.
Feed optimisation, for retail
For e-commerce, the product feed is your biggest lever, because PMax reads your titles, descriptions, images, prices and attributes to decide what to show and to whom. Write titles like search queries (brand, product type and key attributes, not internal SKUs), fill every attribute, and keep prices and stock accurate, or errors and disapprovals quietly pull products from the auction. For retail, an hour on the feed often beats an hour on the ad copy.
The Insights and reporting tabs, and their limits
Use the reporting PMax now gives you to steer the campaign: the channel performance view to catch a channel burning budget, the search terms report to harvest winners into your assets, asset ratings to replace “Low” creative, and placement data to exclude weak Display and YouTube inventory. The limits still apply: reporting can lag, some data stays aggregated, and you cannot control exactly how budget splits between channels.
Performance Max for lead generation (the part most guides skip)
Performance Max can work well for lead generation, but only if you close the loop between a form fill and a real sale. Otherwise it optimises for volume and brings a flood of junk, which is where most lead-gen accounts quietly fail. By default Google counts any submitted form as a conversion and chases more, with no idea which were qualified or spam, so it targets whatever is cheapest, rarely your best customer. The fix is to send lead quality back to Google:
- Import offline conversions from your CRM. When a lead becomes a qualified opportunity or a closed sale, feed that back into Google Ads (offline conversion import or enhanced conversions for leads). Now PMax optimises towards leads that turn into money, not just form fills.
- Use value-based bidding on lead quality. Higher values for leads that reach a real sales stage, low or zero for junk, so bidding chases quality.
- Choose lead-specific goals. Google recommends granular goals such as Submit lead form, Book appointment, Request a quote, Qualified lead and Converted lead, which also switch on its protections against invalid activity (Google Ads Help, Performance Max best practices for lead generation).
- Defend the form. Qualifying questions, reCAPTCHA and server-side validation so obvious spam never becomes a “conversion”.
An illustration (composite, not a specific client): a services business optimises to raw form fills, cost per lead looks great, and the sales team drowns in unusable enquiries. Import qualified-lead and closed-sale data, point bidding at that instead, and the lead count often drops while sales-ready leads rise and cost per qualified lead falls. Fewer leads, more revenue.
One thing that decides lead-gen results sits outside Google: the page you send the click to. PMax only optimises towards conversions that happen, so if your landing page leaks, you pay for clicks that die on arrival. Tightening those pages to turn those clicks into conversions often beats any in-platform tweak.
The mistakes we see most
Most underperforming PMax accounts we rescue share the same short list:
- Weak or broken conversion tracking, so the campaign optimises towards bad data. Number one for a reason.
- Over-segmentation, with too many thin campaigns that never learn.
- Treating PMax as a Search replacement, with no dedicated brand or high-intent Search campaign.
- No brand exclusions, so PMax feasts on brand terms and reports inflated success.
- Poor or lazy creative, with half-empty asset groups and auto-generated video.
- Optimising to form fills in lead gen, with no offline conversion import.
- Impatience, with constant changes that reset the learning phase.
- Reading modelled UK conversions as exact, ignoring consent and Consent Mode v2.
Run Performance Max like it is your money
Performance Max rewards the boring disciplines: clean tracking, honest measurement, strong creative, sensible structure, and the patience to let it learn. Hand it good data and it reaches the whole of Google from one campaign; hand it bad data and it spends confidently in the wrong places, which is most of what we are called in to fix.
If you would rather have it built, measured and managed by people who do this every week, we are a Leicester-based creative and growth agency working with UK businesses across the East Midlands and beyond. The quickest next step is to book a free growth review, and we will look at your account, your tracking and your consent setup, tell you what is leaking budget, and show you what to fix first.