Performance Max has quickly become one of the most talked-about campaign types in digital advertising, promising to bring all of Google’s inventory under one AI-driven roof. For retailers, the opportunity is huge, but so are the challenges of setup, optimization, and proving incremental value. In this Q&A, Filippo Cecchetti, our Director - Digital Marketing, shares practical insights from working hands-on with Performance Max for leading retail clients, covering how to structure campaigns, test creative, and measure growth across channels without falling into common pitfalls.

Q1: What makes Performance Max a game‑changer for full‑funnel campaigns?

Filippo: Performance Max brings all of Google's inventory together in one powerful campaign. Instead of needing to run separate awareness, consideration, and conversion activities, retailers can now let Google's AI work to seamlessly guide shoppers from first impression to final purchase. A customer can discover your brand through an ad on YouTube, be retargeted by a personalized banner ad, and finally convert through a Shopping ad, all within the context of one campaign that's optimizing overall towards your goals.

The real power lies in dynamic budget optimization. Google AI automatically assigns spend to the channel performing best at any moment, whether that's Search, Shopping, Display, or Video. To get the most out of this, retailers need to:

· Monitor and optimize placements (especially in non-brand Shopping) closely to protect incremental growth.

· Test new creatives, structures, and features continuously to stay ahead of the algorithm.

· Segment brand from non-brand activity to prevent overspending on conversions that have low incremental value.

Done correctly, Performance Max not only streamlines campaign management, it transforms it, giving retailers a smarter, always on growth engine.

Relevant insight: Is the Funnel in Digital Marketing Really Dead?

Q2: Can you detail your typical asset group: copy, visuals, audience signals?

Filippo: For our retail customers, we generally structure asset groups by product categories or customer intent segments.

We maximize text assets, 5+ brief headlines on average, several more extended headlines, and 5 descriptions, highlighting principal retail selling points like product name, unique attributes, and special offers (e.g., "Lightweight Running Shoes," "20% Off New Arrivals,""Free Shipping on Orders Over $50"). The objective is to respond to the spectrum of customer intent: from price oriented promotions to brand-forging USPs.

Visuals: In retail, visual content plays a critical role, both in terms of getting engaged as well as for deciding where and when your ads show up. We provide a mix of product images (e.g., clean white background photos for Shopping formats) and lifestyle images (products in action for Display or Discover). Most importantly, we always have at least one video, either brand produced or a light weight edit, since video content unlocks YouTube inventory and continuously expands reach. In fact, providing a deep set of image sizes (landscape, square, portrait) and video enables Google's algorithm to dynamically construct top-performing creative combinations by placement.

The newly available Channel Performance report for PMax makes this even more concrete. It allows us to measure how different creative mixtures affect reach and conversion lift by channel. For instance, adding lifestyle videos drives a higher percentage of impressions on YouTube, while using static product images can skew delivery to Shopping or Display. That feedback loop is gold: we can see, in real time (ish), how creative changes change budget split between channels and can subsequently adjust asset strategy.

Audience Signals: Along with copy and imagery, we add strong audience signals to guide Google's AI. These tend to be Customer Match lists (recent or high-value purchasers), custom segments based on competitor searches or category intent, and Google's in-market audiences. Although PMax will learn off of more than these seeds, giving signals allows the algorithm to start in the right direction, and gives us a handle for testing incrementality.

Learn more about using smart audience signals with predictive intelligence for Google PMax in our Masterclass.

Q3: What’s your process for testing performance — what wins, what doesn’t?

Filippo: When we're rolling out PMax to a retail user, we include a sufficient learning period of 4 to 6 weeks with a set budget and a complete set of best-practice assets. That gives Google's AI time to get up to speed and gain sufficient conversion data. During this stage, we are monitoring top-level KPIs like conversions, CPA, and ROAS but avoid initial two-week knee-jerk reactions as the system still gets calibrated. Adequate daily budget (Google suggests $50–$100+ even on small accounts) is needed – insufficient spend, and PMax can't accumulate the learnings it needs in order to optimize best.

Once the campaign stabilizes, we move into formal testing. We test one variable at a time, for example, swapping in new creative assets or headlines, to isolate what drives performance. If an image consistently ranks as “Best” in Google’s asset report and correlates with higher conversion lift, we’ll double down on that style. Conversely, assets marked “Low” or showing weak engagement get rotated out. The new Channel Performance report does this even more: we can look at how creative tests impact channel mix and assisted conversions. For example, adding in lifestyle video could increase YouTube reach and drive downstream conversions, or product led images could drive spend into Shopping or Display.

Aside from creative, we also incrementality test at the campaign level. This may include geo tests (enabling PMax in one geography vs. turning it off in another) or time-split tests. These testing techniques single out the extent to which PMax is driving the increase in conversions above and beyond other campaigns. For Search- and Shopping-dominated clients, we sometimes A/B PMax against their historic campaigns in Google's experiment tool: half of traffic remains under the legacy setup, while the other half is flowing through PMax. The delta in conversion value or new customer acquisition is compared to determine if PMax is incremental.

In short, our testing protocol is all about patience in the learning phase, rigorous disciplined variable testing, and robust incrementality measurement. This helps us to separate true "wins" from noise slips – and keep refining PMax in the quest for driving incremental, profitable retail growth.

Q4: How do you handle attribution and learnings when PMax mixes multiple channels?

Filippo: One of the initial things that we recommend you do when you're rolling out Performance Max is to get rid of last click attribution. Use data driven attribution (DDA) or some other non-last-click model inside Google Ads. Why? Because PMax acts across multiple touchpoints. Picture a buyer who first sees a Display ad, and then later clicks a Search ad before buying. With DDA, each touchpoint gets equitable credit, so Google's AI knows what really drives conversions and budgets accordingly.

On the other hand, last-click models (or platforms such as Adobe which last-touch attribute by default) overvalue upper-funnel contributions. That makes it hard to measure PMax's true contribution, and can bias tROAS optimization. If last click cannot be eliminated, geo-based incrementality tests are necessary. For example: run PMax in half a country, hold out in the other half, and compare lift in site traffic and conversions. This has the effect of weeding out PMax's true value over and above that exposed by attribution models.

For more depth through reporting to maximize learnings, we take advantage of Google's increasing number of PMax reporting features. The Channel Performance report is especially handy: it breaks out conversions and spend by channel (Search, Shopping, Display, YouTube, Discover). This allows us to see, for example, that of 100 conversions, 70 were achieved through Search and 20 were affected by YouTube and 10 from Display. With ROAS and CPA per channel, we can spot weak links (e.g., a poor-performing Display impressions) and adjust creatives or audience signals accordingly.

We also use asset-level performance and audience data in Google Ads, combined with GA4 for cross channel visibility. Together, these give us the visibility to optimize strategy, demonstrate incrementality, and ensure that PMax is leading true growth, not simply re-allocating credit across channels.

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"Our testing protocol is all about patience in the learning phase, rigorous disciplined variable testing, and robust incrementality measurement."

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Q5: Any tips on avoiding cannibalization of search budget or overlapping campaigns?

Filippo: One of the most pervasive fears that retailers have regarding Performance Max is cannibalization: PMax stealing from branded search or other campaigns. With good setup, you can restrict overlap and get PMax to drive incremental growth.

1. Use Negative Keywords & Brand Exclusions

PMax now incorporates account level negative keyword lists and campaign-level brand exclusions. We use these to keep brand terms and covered keywords out of Search campaigns that are already being served. This prevents PMax from taking credit for conversions that would have been natural. (If exclusions aren't an option in your account, your Google rep can add them manually.)

2. Prioritize Search for Exact Matches

If a user's search query is an exact match of a keyword in your Search campaign, Google will generally display the Search ad over PMax. That means it is critical to cover your high-intent, core keywords in Search, preferably as exact match. Then, PMax captures the long tail or unbidded queries while Search guards your must-win terms.

3. Take Advantage of Shopping Campaign Priority (Where Applicable)

If you are running PMax alongside Standard Shopping, remember Shopping campaigns have priority options. While PMax doesn't directly honor them, if you have Shopping set to High priority, it will get served first for specific products. Even better: remove overlap entirely by maintaining product groups in different segments for PMax and Shopping.

4. Target PMax at Incremental Value

Put PMax where Search can't reach. Lean into YouTube, Display, and Discover for growth at the top of the funnel, or create campaigns for acquisition of new customers utilizing value rules that maximize incrementality in audiences. This ensures PMax is driving growth and not re-warming old demand.

In the end, some overlap is not the apocalypse, sometimes PMax just happens to be a better auction winner than Search. The trick is balance: have Search protect your branded and high intent search, and let PMax go out for new demand and drive incremental growth across Google's ecosystem.

Key takeaways for marketing leaders

The Q&A makes clear that success with Performance Max is about strategy, not shortcuts. For marketing leaders:

· Structure matters: Segment brand vs. non-brand, define asset groups clearly, and monitor budget flows.

· Creativity drives scale: Diverse, high-quality visuals and video give PMax the flexibility to win auctions and audiences.

· Measure smarter: Replace last-click with data-driven attribution and test incrementality to uncover true growth.

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Need help with setting up PMax and AI-driven campaigns for your Paid Search? Reach out to us.

Relevant insights

· Case study: Global Fashion Brand Doubles Paid Search Reach, Driving 81% Revenue Growth Through Broad Match Innovation

· Case study: Driving In-Store Traffic with Paid Search: ETERNA’s Store Visits Campaign Success

· Guide: Mastering Incrementality in 2025 and Beyond: A Practical Guide for Smarter Marketing Decisions

About Crealytics

Crealytics is an award-winning full-funnel digital marketing agency fueling the profitable growth of over 100 well-known B2C and B2B businesses, including ASOS, The Hut Group, Staples and Urban Outfitters. A global company with an inclusive team of 100+ international employees, we operate from our hubs in Berlin, New York, Chicago, London, and Mumbai.