Unlock Google Ads PMax: Audience Signals & Search Themes Explained

Getting the most out of your Google Ads Performance Max campaigns requires a solid grasp of two often-confused features: audience signals and search themes. These tools function more as helpful suggestions for Google’s AI rather than rigid targeting controls. Misunderstanding their role can lead to wasted ad spend and missed opportunities for conversions.

Performance Max operates on a fundamentally different principle than other Google Ads campaign types. You do not get to pick your audience or keyword targeting in PMax. This is a goal-based system where the primary objective is to achieve your specified conversion goal. The campaign’s underlying technology, powered by optimized targeting and dynamic search, autonomously decides who sees your ads based on their predicted likelihood to convert. Your conversion tracking setup and chosen bid strategy are the true drivers of your ad delivery.

Think of audience signals as giving Google’s AI a helpful nudge , a way to combine your business insights with machine learning. In the interface, these signals look much like traditional audience targeting and can include your data segments, such as Customer Match lists, people who have engaged with your YouTube channel, or past website visitors.

The key difference is that these are signals, not rules. The AI can move beyond them if it identifies better-performing audiences. If you signal an affinity for “luxury shoppers” but the system discovers that “value shoppers” convert more efficiently, it will prioritize the latter. The campaign’s only goal is to drive conversions , which is why accurate conversion tracking is absolutely critical.

The same logic applies to search themes. These are not keywords in the traditional sense. In a standard Search campaign, keywords act as strict gatekeepers determining which queries trigger your ads. In Performance Max (PMax), a search theme is simply a hint , an optional suggestion about the types of searches your ideal customers might use. If those queries generate conversions, the campaign will keep showing ads for them; if not, it will automatically pivot toward more effective ones.

Search themes can be useful when you’re launching a new campaign, introducing a new product, or signaling interest in competitor-related searches. Still, adding dozens of irrelevant themes that don’t produce results won’t hurt the campaign , it will just ignore them and shift budget to what works.

Because signals are not the main control mechanism, your focus should remain on the elements that truly guide PMax performance , starting with conversion tracking. It serves as the campaign’s compass and must be set up to measure actions that reflect genuine business value.

You should still use audience signals and search themes, especially when starting fresh or leveraging strong first-party data like Customer Match lists. Just remember: PMax may serve ads outside your provided signals if the AI finds more promising prospects. Never mistake signals for hard targeting.

A common misstep is running multiple asset groups within a single PMax campaign that all use the same creative assets but different audience signals or search themes. This only fragments the AI’s learning and wastes budget on duplication. The reason to create a separate asset group should be a meaningful difference in creative content or product mix, not merely a change in signals. You can assign different signals to different groups , or the same ones across all , but the defining factor must always be the assets themselves.

(Source: Search Engine Land)