Performance Max (PMax) is a core campaign type in almost every Google Ads account today, but leaving it entirely unsupervised is a recipe for wasted spend. In 2026, the best media buyers aren’t fighting the AI; they are actively steering it.

The most powerful tool for guiding Google’s algorithm is Search Themes. Here is how to use them to unlock highly targeted traffic without sacrificing the efficiency of automation.

1. What Are Search Themes?

Introduced as a way to map out intent before PMax learns it the hard way, search themes allow you to explicitly tell Google AI which topics, products, and audiences matter most to your business. Google assigns search themes the exact same prioritization level as phrase match and broad match keywords in traditional Search campaigns. You can now add up to 50 search themes per asset group.

2. When to Deploy Search Themes

Search themes are not just a safety net; they are an aggressive scaling tactic. They are particularly crucial in three scenarios:

• New Product Launches: When you are entering a new market or launching an item with zero performance history, search themes supply the immediate signal that Google’s AI needs to find buyers.
• Seasonal Promotions: During short-term sales events (like Black Friday), campaigns don’t have time to slowly gather historical data. Search themes bridge that gap immediately.
• Incomplete Landing Pages: If your website doesn’t explicitly spell out every nuance of your service, search themes explicitly tell Google what the page is actually about.

3. Installing Guardrails

Search themes expand your reach, but that expansion must be kept accountable. Always pair your search themes with robust campaign-level negative keywords and brand exclusions. This ensures that while Google is exploring new pockets of demand across Search, Display, and YouTube, it isn’t cannibalizing your branded traffic or bidding on irrelevant terms.