Performance Max (PMAX) campaigns have become one of the most talked-about tools in the Google Ads Pay Per Click ecosystem. By leveraging Google’s machine learning to serve ads across Search, Display, YouTube, Gmail, Discover, Maps, and Shopping — all from a single campaign.
PMAX can deliver more all-round results often at cheaper costs, and it can also allow businesses a broader reach across platforms they have not considered before.
Many advertisers jump into PMAX expecting an instant and rewarding experience, only to burn through their budgets with little to show for it. If you want to get real results from Performance Max, here are the most common mistakes you need to avoid.
Setting Vague or Incorrect Conversion Goals (Or Even None!)
PMAX is a goal-based campaign type. Google’s algorithm optimises everything including the bidding, targeting and the advert placements, but generally they do this around the conversion goals you set. If your conversion tracking is misconfigured, or if you’re optimising for low-value actions like page views instead of meaningful conversions like purchases or qualified leads, the algorithm will chase the wrong outcomes and spend your budget in the wrong areas.
What to do instead:
- Ensure your conversion tracking is properly set up and verified before launching.
- Prioritise high-value conversion actions (e.g., purchases, form submissions) as your primary goals.
- Use conversion value rules if different conversions carry different business value.
Providing Weak or Limited Creative Assets
PMAX relies on asset groups which are combinations of headlines, descriptions, images, videos, and logos to dynamically build ads across channels. If you only provide the bare minimum, or if your assets are low-quality, your campaign performance can suffer because PMAX does not have enough creative material to work with.
Whilst Quality Score in the old days was important, making sure you give PMAX quality assets is now the thing you need to concentrate on.
What to do instead:
- Upload the a decent number of assets allowed in each category.
- Use high-resolution images and professionally produced videos if these are available for your business.
- Write a good range of headlines and descriptions that speak to different audience pain points and motivations.
- Regularly review asset performance ratings and replace underperformers.
Ignoring Audience Signals
One of the biggest misconceptions about PMAX is that it handles all targeting automatically. While Google’s AI does expand beyond your initial inputs, audience signals are critical hints that tell the algorithm where to start looking.
So many businesses fail to put these in (think of them as keywords for search), which then means your campaign will run away chasing the wrong aspects and therefore spending all your budget with little or no returns.
What to do instead:
- Add custom segments based on search themes, website visitors, and customer lists.
- Make sure you focus in on demographic and interest-based signals relevant to your ideal customer.
- Think of audience signals as keywords to train the system where you want to focus your budget and bidding on..
Not Giving the Campaign Enough Time to Learn
PMAX campaigns go through a learning period where Google’s PPC algorithm tests different combinations of assets, audiences, and placements. Many advertisers panic when they don’t see immediate results and start making drastic changes or end up pausing the campaign, slashing budgets, or swapping out all assets. This resets the learning phase and wastes the data already collected.
What to do instead:
- Allow at least 2 months before making major judgments on performance.
- Avoid making more than one significant change at a time.
- Monitor trends rather than daily fluctuations.
Relying Solely on Automation Without Oversight
PMAX is powerful, but it’s not infallible. Google’s AI optimises for the goals you give it, but it doesn’t understand your brand, your margins, or your business strategy. Just trusting the algorithm without regular check-ins can lead to wasted spend on irrelevant placements, brand-unsafe environments, or audiences that don’t convert downstream.
What to do instead:
- Review placement reports and search term insights regularly.
- Use brand exclusions and negative keywords (now available for PMAX) to filter out irrelevant traffic.
- Cross-reference Google Ads data with your CRM or analytics platform to validate lead quality.
Running PMAX Without a Product Feed (For E-Commerce)
If you’re in e-commerce and running PMAX without linking your Google Merchant Center product feed, you’re missing out on the campaign’s most powerful capability: Shopping and product-based placements. PMAX when combined with a product feed unlocks dynamic product ads (shopping) across Google’s entire network.
What to do instead:
- Make sure you connect your Google Merchant Center account and ensure your product feed is optimised with accurate titles, descriptions, pricing, and high-quality images.
- Make sure you focus on the feed and product quality, as these can really impact the success of an ecommerce campaign.
- Segment your products into asset groups for better control and reporting. You can split into product type, brand, price or a wide range of metrics to really help push what your business needs to push at any one time.
Using PMAX as Your Only Campaign Type
PMAX on its own is a very solid approach to Google Ads, but we believe it is designed to complement your existing campaign strategy, not replace it entirely. Running PMAX in isolation means you lose the granular control and insights that come with dedicated Search, Display, or YouTube campaigns.
What to do instead:
- Use PMAX alongside standard Google Ads Search campaigns for your highest-priority keywords.
- Maintain dedicated campaigns where you need more control over messaging, bids, or placements.
- Use PMAX to discover new audiences and channels, then scale proven strategies with dedicated campaigns.
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