Auditing the Performance Max black box: A strategic approach

Google Ads Performance Max campaigns are often called a “black box” due to their:

• Heavy automation.
• Limited transparency.
• Reduced control over traditional campaign levers.

This inherent opaqueness can make auditing these campaigns challenging, leaving many businesses feeling like they’re flying blind.

However, the need for audits doesn’t disappear; it simply shifts. 

To effectively audit Performance Max, we must move beyond conventional performance metrics and levers and look at the foundational elements that feed the campaign, because, as many PPC practitioners say, “Garbage in, garbage out.”

This article provides a structured audit checklist to help you navigate the complexities of Performance Max campaigns. 

It’s designed to bring clarity and focus, guiding you through the most critical components for a thorough and effective analysis.

Concentrating on key inputs, proper setup, and available data can extract meaningful insights and deliver real value, even with limited visibility into campaign mechanics. 

You don’t need to cover every item, but prioritizing the areas most relevant to your business or client will enable a more targeted and insightful audit.

Ultimately, this checklist is meant to help you move beyond vague observations and provide concrete, actionable takeaways when evaluating Performance Max campaigns.

Technical and tracking setup

Conversion tracking – validate the gtag.js and Google Ads conversion tracking code 

• How to check
  • Use Google Tag Assistant Legacy or the Diagnostics section within your Google Ads account under Goals > Diagnostics to verify the firing of your gtag.js and conversion tags.
• Why it’s important
  • Accurate conversion tracking is the lifeblood of Performance Max, as it directly feeds the machine learning algorithms that optimize your bids and targeting to drive your desired business outcomes.

Validate that enhanced conversion tracking has been set up.

• How to check
  • In Google Ads, navigate to the Diagnostics section within your Google Ads account under Goals > Diagnostics to verify.
• Why it’s important
  • Enhanced conversions improve the accuracy of your conversion measurement by capturing more precise first-party data, which is crucial for maximizing the effectiveness of Performance Max’s machine learning, especially in a privacy-centric environment.

Make sure attribution to data-driven

• How to check
  • In Google Ads, go to Google > Attribution > Attribution models, and confirm that Data-driven is selected as your default reporting attribution model.
• Why it’s important
  • Data-driven attribution credits conversions based on how different touchpoints contribute to the conversion path. This provides Performance Max with a more nuanced understanding of user behavior, enabling more effective optimization across all ad interactions. 
  • Whether you like it or not, this campaign effectively leverages all of Google’s channels. 
  • However, if the system fails to recognize the contributions of upper-funnel channels, the core premise of Performance Max will be undermined.

Verify GA4 implementation and linking to your Google Ads account

• How to check
  • In your GA4 property, go to Admin > Product links > Google Ads Links to confirm your Google Ads account is connected, and then check real-time reports to ensure data is flowing.
• Why it’s important
  • A properly linked and implemented GA4 property provides Performance Max with a richer understanding of user behavior on your website beyond just conversions, feeding valuable signals for audience targeting and overall campaign optimizations.

For lead gen: Check that lead quality is tracked and value updates are automatically sent to Google

• How to check
  • Confirm that your CRM or lead management system is integrated with Google Ads via offline conversion import or the Google Ads API. 
  • Look for evidence that actual lead quality or revenue data (e.g., deal stage progression, closed-won opportunities) is being sent back to Google Ads, either manually or through an automated process.
• Why it’s important
  • By sending lead quality and value data back to Google, Performance Max’s Smart Bidding can do more than focus on lead volume – it optimizes for lead value. 
  • This allows the algorithm to prioritize higher-quality prospects who are more likely to convert into paying customers, ensuring you maximize your return on ad spend.

Dig deeper: 7 tips for conducting Google Ads audits

Merchant center and feed management

Check that the Merchant Center is connected

• How to check
  • In your Google Ads account, navigate to Tools > Data manager. 
  • Under Connected products, look for Google Merchant Center and confirm its status. 
  • You can also check in Google Merchant Center under Settings (gear icon) > Linked accounts or Apps and services.

• Why it’s important
  • A validated connection between Google Ads and Merchant Center is fundamental for Performance Max to access and utilize your product data for Shopping ads and other dynamic formats.

Check for optimized product feed (e.g., adding short titles for Discovery/Gmail)

• How to check
  • Review your product feed in Google Merchant Center, paying close attention to attributes like title, description, and the presence of short_title and lifestyle_image_link. 
  • Compare these to Google’s best practices for comprehensiveness and keyword relevance, especially for various ad formats.
• Why it’s important
  • An optimized product feed equips Google’s AI with detailed, high-quality data, enabling the creation of more diverse ads across various placements. 
  • This extends reach beyond traditional Shopping results, tapping into the Performance Max upper funnel channels for greater impact.

Label products in your feed based on specific objectives (i.e., profit margins or other priorities)

For instance, you might separate lower-cost accessories from your primary product line to better align with your strategy. 

This approach also makes it easier to isolate specific products for targeted campaigns.

• How to check
  • In Google Merchant Center, review your product data for the use of custom_label_0 through custom_label_4 attributes. 
  • Verify that these labels are being applied consistently to segment products according to strategic criteria like margin, seasonality, or performance.
• Why it’s important
  • Custom labels enable granular control within Performance Max, allowing you to:
    • Segment product sets.
    • Adjust bidding strategies.
    • Allocate budget more strategically.
  • This lets you achieve specific business objectives, such as maximizing profit on high-margin items or pushing clearance stock.

Ensure your feed is being updated frequently 

• How to check
  • In Google Merchant Center, navigate to Products > Manage Data Sources. 
  • Select your primary feed and examine the Schedule or Last fetch details to see how often your feed is being processed. 
  • For dynamic inventory, also check if Automatic item updates are enabled.

• Why it’s important
  • Frequent feed updates ensure that your product information (pricing, availability, condition) is always current.
  • This prevents disapprovals, avoids wasted ad spend on out-of-stock items, and ensures that Performance Max optimizes based on the most accurate and up-to-date product data.

Check that no top-selling products are disapproved.

• How to check
  • In Google Merchant Center, navigate to Products > Diagnostics or All products. 
  • Filter by Disapproved status and sort by Clicks or Conversions (if available) to quickly identify if any historically high-performing products are currently disapproved. 
  • Cross-reference this with your internal sales data or a top-seller report from your ecommerce platform.
• Why it’s important
  • If Performance Max attempts to promote items that cannot be shown, disapproved top-selling products directly lead to missed sales opportunities and wasted ad spend. 
  • Ensuring all top sellers are approved is critical for campaign effectiveness and revenue generation.

Check that no top-selling products are out of stock

• How to check
  • Within Google Merchant Center, go to Products > Diagnostics and filter for Out of stock issues. 
  • Prioritize this list by cross-referencing with your top-selling product data from your ecommerce platform to identify any key products with availability issues.
• Why it’s important
  • Performance Max’s AI cannot sell out-of-stock products. 
  • Promoting unavailable top-selling items:
    • Frustrates potential customers.
    • Wastes ad budget.
    • Reduces the overall efficiency and profitability of your campaigns.

Campaign structuring and settings 

Check the current campaign structure (e.g., how many PMax campaigns, their focus, and their keyword sprawl)

• How to check
  • Review the list of Performance Max campaigns in your Google Ads account.
  • Analyze:
    • Naming conventions.
    • Asset group focuses.
    • Search themes.
    • Whether they are set up for specific product categories, services, or conversion goals. 
  • Evaluate if the current structure aligns with the business’s overall marketing objectives.
• Why it’s important
  • A well-thought-out Performance Max campaign structure:
    • Allows for clearer goal segmentation, better budget allocation, and more precise reporting. 
    • Prevents campaigns from competing against each other or diluting the impact of your ad spend.
  • By centralizing product lines into a single PMax campaign with distinct asset groups, you aim to:
    • Minimize keyword cannibalization.
    • Improve the relevance of ads served.
    • Allow Google’s AI to optimize more efficiently across related products.
    • Maintain better control over the types of search terms your ads appear for, even within PMax’s broad targeting.
  • While separate ROAS targets can be a valid reason for separate campaigns in some scenarios, the risk of search term overlap and cannibalization in PMax often outweighs the perceived benefits of independent campaigns for closely related product lines.

Ensure standard search campaigns are set up and working properly (and generating enough conversions to inform PMax)

• How to check
  • Examine your existing Standard Search campaigns for:
    • Active status.
    • Healthy impression.
    • Click volume.
    • Consistent conversions and results. 
  • Look at their conversion volume and cost-per-conversion, and ROAS to assess their stability and contribution to the account goals.
• Why it’s important
  • While Performance Max focuses on finding new conversions, well-performing standard search campaigns play an important supporting role. 
  • They provide valuable historical data and audience signals that help train and improve Performance Max’s machine learning, especially when those audience signals are used in the campaign.

Check that advanced location targeting is set to ‘Presence: People in or regularly in your targeted locations’

• How to check
  • Navigate to the Locations settings within your Performance Max campaign settings. 
  • Click on Location options (Advanced settings) and verify that Presence: People in or regularly in your targeted locations is selected under Target.
• Why it’s important
  • This specific location setting ensures that your ads are shown primarily to users physically located within or frequently visiting your target areas. 
  • This maximizes the relevance of your ads and prevents wasted spending on users who are only interested in your location.

For lead gen: Check for the use of UTM parameters at the asset group level for CRM tracking in settings

• How to check
  • Review the final URLs or tracking templates within each asset group in your Performance Max campaigns. 
  • Verify that custom UTM parameters (e.g., utm_source, utm_medium, utm_campaign, utm_content) are consistently applied to help identify the source of leads in your CRM.
• Why it’s important
  • Effective UTM tagging is essential for accurately tracking the source and performance of your leads beyond basic conversions. 
  • It provides valuable insights into which specific Performance Max asset groups are delivering the highest-quality leads to your CRM. 
  • Given the prevalence of spam online, lead generation must be both highly accurate and easily trackable. This should be a key focus in any non-ecommerce Performance Max audit.

Dig deeper: How to automate your Google Ads workflow with the ChatGPT API

Creatives and audiences: The crux of Performance Max

Check for diverse asset groups (headlines, long headlines, descriptions, images, videos)

• How to check
  • Within each Performance Max campaign, navigate to your asset groups and review the variety and number of:
    • Headlines.
    • Long headlines.
    • Descriptions.
    • Images (including different aspect ratios).
    • Videos. 
  • Look for assets with a range of messaging, visual styles, and lengths.
• Why it’s important
  • Performance Max excels at dynamically crafting ads across a wide range of placements, much like a game of Tetris with advertising. 
  • By providing a diverse set of high-quality assets, it equips the AI with the tools to create highly relevant and engaging ads tailored to different audience segments and contexts. 
  • This approach enhances both ad strength and overall performance.

Check for strong calls to action (CTAs)

• How to check
  • Review the asset details within your asset groups, specifically focusing on the CTAs used. 
  • Evaluate if they are clear, concise, compelling, and relevant to the desired conversion action (e.g., “Shop now,” “Learn more,” “Get a quote”).
• Why it’s important
  • Clear, persuasive CTAs are absolutely essential for engaging your audience and guiding them toward the next step you want them to take. 
  • Here’s the best part – when done right, they can directly boost your conversion rates and elevate the overall performance of your Performance Max campaigns. 
  • I’ve seen it time and again with clients: a well-crafted CTA isn’t just a small tweak; it’s a game-changer.

Check for relevant extensions

• How to check
  • In your Google Ads account, navigate to Assets > Asset coverage tab, and scroll down to any asset group that needs improvement.

• Why it’s important
  • Ad extensions enhance your advertisements by providing additional information and interactive elements, improving visibility and click-through rates. 
  • Within the Performance Max campaigns, they serve a dual purpose:
    • Offering users more opportunities to engage with your ad.
    • Supplying the AI with valuable data points to optimize ad delivery. 
  • Historically, ad extensions have been described as an effective, cost-free method to increase the size and impact of your advertisement, making them a strategic tool for maximizing performance.

Check for the presence of a customer-match audience of existing customers.

• How to check
  • In Google Ads, navigate to Tools > Shared Library >
    Audience manager. 
  • Look for Customer lists and verify that an audience list comprised of your existing customer data has been uploaded and is active, ideally with a healthy match rate.
• Why it’s important
  • A customer match audience provides Performance Max with invaluable first-party data. 
  • This acts as a powerful signal, guiding the AI to find new, similar high-value prospects who are more likely to convert, leveraging the insights from your current customer base.

Check for a custom segment audience based on converting search terms

• How to check
  • In Google Ads, navigate to Tools > Shared Library > Audience manager.
  • Look under Custom segments for an audience that specifies keywords or search terms that have previously led to conversions. 
  • Verify that these terms are relevant and significant for your business.
• Why it’s important
  • Custom segments based on converting search terms give Performance Max a strong indication of user intent that has proven valuable. 
  • This helps the campaign identify and target new users with similar successful search behaviors, expanding reach with a higher likelihood of conversion.

Website and landing page experience

Check that your website is mobile-friendly

• How to check
  • Use Google’s Mobile-Friendly Test tool (search for “Google Mobile-Friendly Test”) and enter your website’s URL. 
  • Also, manually browse your site on various mobile devices and screen sizes to ensure proper rendering, readability, and navigation.
• Why it’s important
  • A mobile-friendly website is critical for Performance Max as a significant portion of its impressions occur on mobile devices. 
  • A poor mobile experience leads to high bounce rates, wasted ad spend, and negatively impacts your campaign performance.

Check that forms and/or checkouts work 100%

• How to check
  • Conduct thorough manual testing of all conversion-critical elements on your landing pages, such as:
    • Lead forms. 
    • “Add to cart” buttons.
    • The entire checkout flow. 
  • Perform test submissions/purchases on different browsers and devices to identify any glitches or broken steps.
• Why it’s important
  • Faulty forms or checkout processes directly block conversions, rendering your ad spend ineffective. 
  • Performance Max relies on conversion data to optimize.
  • If the final conversion step is broken, the campaign cannot learn or achieve its objectives, leading to a significant waste of budget.

Exclusions and negative keywords, plus brand strategy considerations

Check for brand exclusion from campaign (if running separate brand campaigns) and review Shopping ad settings for excluded brands

• How to check
  • In your Google Ads account, navigate to the specific Performance Max campaign settings. Look for Additional settings and then Brand exclusions. 
  • Verify if any brand lists are applied. Crucially, check the checkbox option below the brand list selection that states, “Allow Shopping ads on searches that mention excluded brands.” 
  • Confirm if this box is checked or unchecked based on the desired strategy for brand Shopping queries.
• Why it’s important
  • Properly managing brand exclusions ensures that Performance Max aligns with your broader brand strategy. 
  • This is particularly vital for Shopping inventory, where you can choose to allow brand-related Shopping ads to run through PMax (leveraging its broad reach) even if you’ve excluded brand terms from its search inventory (to preserve control in dedicated brand search campaigns). 
  • This prevents cannibalization while still capturing valuable high-intent Shopping traffic.

Dig deeper: How AI makes paid search audits faster and better

Key Performance Max specific reports and insights

Check the quality and rotation of existing assets

• How to check
  • Navigate to your Performance Max campaign, then go to the Asset groups tab. Click View details for each asset group to access the asset report. 
  • Review the Performance column for each asset (headline, long headline, description, image, video) to identify assets rated as “Low” or “Poor.”
• Why it’s important
  • Assets with “Low” or “Poor” performance ratings can drag down the overall effectiveness of your Performance Max campaign. 
  • Identifying these allows you to recommend replacing or improving them, ensuring the AI has the best possible creative building blocks to generate high-performing ads.

Review campaign change history for bidding target and budget updates

• How to check
  • In your Google Ads account, go to Change history. 
  • Filter by your Performance Max campaign(s) and specific change types like Budget changes and Bidding changes, and review the frequency and rationale behind these adjustments.
• Why it’s important
  • Regular, strategic adjustments to bidding targets and budgets indicate proactive management and a responsiveness to performance trends. 
  • This audit helps confirm that the campaign’s financial levers are being actively monitored and optimized rather than left stagnant.

Review the Channel Performance report

• How to check
  • Select a Performance Max campaign. In the left-hand menu, under Insights and reports, select Channel performance. 
  • To understand how different channels (Search, Display, YouTube, Discover, Maps, Gmail) are contributing to your conversion goals, examine:
    • The campaign-level performance summary.
    • The Channels-to-Goals chart.
    • The channel distribution table.
• Why it’s important
  • While you can’t directly control channel allocation in Performance Max, this report provides crucial transparency into where your budget is being spent and which channels are driving results. 
  • This insight is vital for contextualizing performance for clients, informing broader marketing strategies, and identifying potential areas for further asset refinement if certain channels are underperforming due to creative gaps.

Review Audience Insights report

• How to check
  • In your Performance Max campaign, navigate to Insights and reports, then select Audience insights. 
  • Review the data on demographics, interests, and behaviors of users interacting with your ads.
  • Pay particular attention to segments labeled “Optimized” (which Google’s AI has discovered) and those that have strong conversion rates.
• Why it’s important
  • Understanding which audiences Performance Max is effectively reaching and converting provides valuable intelligence. 
  • This helps you:
    • Identify new potential audience signals to feed the campaign.
    • Refine your messaging.
    • Even inform broader business strategy, ultimately leading to more efficient customer acquisition.

Review Suggested Trends and Explanations in the Insights section.

• How to check
  • Access the main Insights page within your Google Ads account or directly within a Performance Max campaign. 
  • Look for Suggested trends that highlight upcoming demand forecasts relevant to your business.
  • Utilize Explanations (often found when hovering over blue, dotted-line performance metrics) to understand significant performance shifts.
• Why it’s important
  • These insights, especially Suggested trends, offer forward-looking data to plan for inventory, promotions, and landing page updates, allowing you to proactively align your campaign with predicted demand. 
  • Explanations provide Google’s direct interpretation of “why” performance changed, which is invaluable for understanding the black box and troubleshooting.

Review past seasonality adjustments

• How to check
  • In Google Ads, navigate to Tools > Budgets and bidding > Adjustments. Select the Seasonal tab at the top. 
  • Review any past seasonality adjustments that were applied, noting their dates, duration, and the conversion rate adjustment percentage.
• Why it’s important
  • Seasonality adjustments are critical for informing Smart Bidding about expected spikes or dips in conversion rates during promotional periods or seasonal events. 
  • Auditing past adjustments confirms that the account is proactively leveraging this tool to optimize performance during key business cycles and prevent over- or under-bidding.

Auditors are the missing link in Performance Max success

Performance Max campaigns are a game-changer in paid search, blending automation with Google’s AI. 

While their “black box” reputation can make them feel like a departure from traditional campaign management, there’s still plenty of room for us, as paid search marketers, to make a big impact through strategic oversight.

Regular and thoughtful audits are more important than ever.

Sure, we may not have the same hands-on control as with other campaign types, but our role shifts from daily optimizations to guiding the campaign strategically. 

It’s all about focusing on the essentials: the quality of the inputs we provide, the accuracy of the tracking data, and aligning campaign settings with bigger business goals. 

When we nail down these foundational elements, we set the stage for success.

This checklist is your tool for exactly that – breaking down your audit into actionable steps. 

Whether you’re examining your technical setup, feed health, creative assets, or audience signals, each item serves as a building block for better performance. 

Reviewing channel insights, fine-tuning conversion tracking, and understanding Google’s own data are also key to understanding the full potential of Performance Max. 

And don’t worry – you don’t need to tackle everything all at once. Prioritize what matters most for your business or client, and you’ll deliver insights that truly move the needle.

Even with all the automation, the human touch remains invaluable. 

Our job as experts is to focus on what we can control, make the most of the data we do have, and translate performance into actionable insights for stakeholders. 

At the end of the day, thoughtful audits and informed strategy are what turn a tool into meaningful results. 

With the right approach, Performance Max can deliver value – and you’re the one who has to make that happen.