How to Optimise Your PMAX Campaigns for UK Audiences: A Practical Guide

You’d be forgiven for feeling a bit daunted the first time you open Google Ads and try to wrap your head around PMAX campaigns. Performance Max isn’t your usual Search or Shopping territory; it’s a sprawling, AI-driven beast determined to cover every corner of Google’s properties. From Maps to YouTube to Gmail. If that sounds powerful but a little wild, you’d be bang on. The flexibility is brilliant for reach, but it brings challenges, especially here in the UK where audience behaviour and local nuance can make or break your ROI.

Let’s get right to it: what sets PMAX apart, and how can you ensure these campaigns don’t eat up your budget for breakfast?

What Makes PMAX Campaigns Different?

PMAX campaigns are designed to serve ads across all Google channels with a single campaign. That means your budget, creative, and targeting are all mashed together in one powerful cocktail, letting Google’s AI make the calls on where your ads appear for the best chance at a conversion. Sounds hands-off, right? But here’s the catch: the same AI that optimises for conversions can also run wild if not given crisp boundaries.

You won’t get the same granular control as you do with Search or Shopping campaigns. You give Google your goals and some signals, it runs off to do its magic. The trade off? Precision for efficiency. In my own experience managing campaigns for a mid-sized retailer based in Manchester, the initial ‘set and forget’ mentality backfired. PMAX vacuumed up budget by pushing spend on less valuable placements. Like broad Discovery network clicks. At the expense of tried-and-true Shopping traffic.

Setting Up Audience Signals and Location Targeting: Why Local Relevance Isn’t Optional

Here in the UK, location really matters. You can’t treat Greater London and the Midlands the same way, let alone think an ad for raincoats in Cornwall will have the same pull in sunny Brighton as it does up in Glasgow.

Audience signals, though not traditional targeting, act as hints for Google’s AI. Feed it carefully curated first-party data. Email lists, past converters, or those who linger on your site. For example, I’ve achieved the best results when segmenting audience signals by region, using local store data for a nationwide high street brand. Match these with location targeting set strictly to “Presence: People in or regularly in your targeted locations”. Not just folks interested in them. Cutting out the “presence or interest” setting helps avoid the bloated impressions from accidental overlap with tourists or expats simply researching UK terms.

A quick tip: always double-check that Google hasn’t sneakily broadened your geo targets during campaign creation. It happens, and it’s a surefire way to burn through budget with irrelevant clicks.

Structuring Your Campaigns to Prevent Cannibalisation and Overspending

Letting PMAX run rampant with a single campaign is a surefire path to cannibalisation. That means your PMAX ads may overlap with your own Search, Shopping, or even Local campaigns, bidding against yourself and muddying the results.

Here’s how I structure campaigns for clarity:

• Separate out product categories or service lines. Don’t lump them all together.
• Exclude brand or best-performing search terms from PMAX, reserving those for your exact match campaigns with more control.
• If possible, run separate PMAX campaigns for distinct regions. What works in Liverpool might flop in Bristol.

This approach has saved clients thousands in wasted spend, allowing for tighter measurement and cleaner reporting.

Creative Assets That Shine Across Google Channels

The UK audience is a discerning lot. Quick to scroll past generic, US-centric adverts, and even quicker to engage with creative that feels relevant. PMAX campaigns rely on a blend of images, video, headlines, and long-form text, all dynamically mixed by Google.

Based on research and hands-on testing, here’s what’s performing best right now across YouTube, Display, and Discover:

Authenticity counts: Use assets that reflect British life. I’ve seen outperforming ads using rainy city scenes or everyday UK moments, as opposed to those impossibly blue Californian skies.
Short, bold headlines: Steer clear of clichés; plain English often does better. A headline like “Need a new telly for the Euros?” speaks to local context and events.
Video matters: Even basic vertical video shot on a decent smartphone provides a huge lift, especially with YouTube placements. Try short clips, not elaborate productions.
Get the specs right: Avoid chopped-off text and fuzzy images by following Google’s asset guidelines exactly. A surprising number of advertisers still send assets with the wrong aspect ratio or blurry resolution.

And don’t forget: update your creatives regularly. Trends move quickly, and stale ads tend to slide down the performance ladder fast.

Interpreting PMAX Reporting: Reading Between the Lines

PMAX’s notorious “black box” reputation can leave you scratching your head. You might wonder, how do you know what’s actually performing well? Google provides only so much in-platform visibility. No channel-level breakout by default, limited search term details, and the odd incomplete conversion path.

In my experience, digging into the “Insights” tab provides the best clues. Pay careful attention to:

• Top-performing search categories (even if exact queries are hidden)
• Asset group diagnostics
• Audience segment performance and location data

Pair this with data from your own CRM or analytics platform, mapping conversions back to campaign traffic where possible. I’ve built custom dashboards for clients specifically to bridge these gaps, surfacing which products or regions are actually powering results.

It pays to get comfortable with ambiguity. Rather than chasing every data point, focus your optimisations where you can see clear movement: creative refreshes, audience signals, location tweaks, and budget shifts between campaigns.

The Takeaway for UK Marketers

PMAX campaigns are powerful, but they’re not “set and forget”. Especially in the ever-quirky UK digital landscape. Whether you’re hustling for a bustling agency in East London or running paid ads for your own small business in Leeds, the core strategies remain the same: get your signals and targeting right, keep creative fresh, and stay on top of your reporting.

If you’re ready to squeeze more out of your campaigns, start with a small test, get your house in order with assets and audience lists, and don’t be shy about pulling the plug on anything that isn’t delivering. After all, every pound spent should be moving the needle toward more conversions, not just more clicks.

Want your next PMAX campaign to actually shift results? Now’s the time to roll up your sleeves, lean into the data, and let some local flavour guide your ads.

Frequently Asked Questions

How can I stop my PMAX campaigns from stealing budget from Search and Shopping campaigns?

One of the best steps is to exclude high-value branded or exact match keywords from PMAX using account-level negative keywords or campaign exclusions. You could also split out product categories and avoid lumping everything into one campaign. Careful structuring goes a long way to avoid cannibalisation.

Are there UK-specific audience signals worth trying?

Absolutely. If you’ve got access to past purchasers, loyalty scheme members, or local store visitors, these make great custom signals. Including postcodes, regional email segments, or even targeting by key UK events can help make your signals much more relevant.

What types of creative assets perform best for UK audiences on PMAX?

Assets that reflect local culture or real-life scenarios do much better. Think British settings, weather, or common slang in headlines. Short, sharp copy and authentic video. Sometimes even selfie-style. Outperform glossy, corporate-feeling ads.

How do I check if PMAX is driving true conversions rather than just clicks?

Leverage offline conversion tracking where you can, and link Google Ads with your CRM system. Focus on end-to-end customer journeys, not just what Google reports as conversions. Periodically review actual sales or enquiries attributed to PMAX to see if they align with your paid results.

Can I trust PMAX reporting for granular optimisation decisions?

PMAX reporting can be limited, so it’s best to combine Google’s insights with data from your analytics stack. While PMAX offers some breakdown, you’ll need to use asset group diagnostics and performance trends to make informed adjustments. Trust your own sales data as the final word wherever possible.