Understanding Google PMAX Campaigns

• Asset Group: A collection of creative assets (text, images, videos) centered on a theme, replacing traditional ad groups. For maximum optimization, all of the following should be included.
  • Headlines: Each asset group requires fifteen (15) headlines that are less than or equal to 30 characters, including spaces. Headlines should be title case and should not contain punctuation. An "&" is ok to use in place of "and."
  • Long Headlines: Five (5) long headlines, less than or equal to 90 characters in length, are required per asset group. Like headlines, they should be title case and should not contain punctuation. An "&" is ok to use in place of "and."
  • Descriptions: Each asset group requires five (5) descriptions that are less than or equal to 90 characters. Descriptions should be written in sentence case and can contain punctuation. Think of them as short paragraphs.
  • Images: Up to 20 images can be added to a campaign. A combination of horizontal, vertical and square images is required for an optimal quality score.
  • Videos: Because PMAX campaigns can also run on YouTube and other video channels, a minimum of 5 videos should be included. At least one video in each of these sizes: 1920x1080 (horizontal); 1080x1920 (vertical); 1920x1920 (square).
• Audience Signals: Data inputs (e.g., remarketing lists, customer match) provided to AI to accelerate learning and targeting, though not restricted to them.
• Asset Reporting: Data showing how individual creatives (headlines, images) perform.
• Ad Strength: An indicator (e.g., "Poor" to "Excellent") of how relevant and comprehensive your asset group is. 
   

Bidding & Optimization

• Smart Bidding: Machine learning-driven bidding (Maximize Conversions or Value) that acts campaign-wide rather than at the asset group level.
• ROAS (Return on Ad Spend): Revenue generated divided by ad spend.
• Marginal CPA/ROAS: Cost or return on additional conversions, used to measure marginal performance.
• New Customer Acquisition Goal: Bidding to acquire new customers over focusing on existing customers. 
   

Targeting & Control

• Search Themes: PMax allows adding up to 25 search themes per asset group to inform Google AI about topics users search for.
• Negative Keywords: Now allowed in PMax, letting you block irrelevant terms to improve brand safety.
• Brand Exclusions: Settings to prevent ads from appearing for specific branded search queries. 
   

Performance Metrics

• Inventory/Channel: The specific Google platform where an ad appeared (e.g., YouTube, Gmail, Search).
• Final URL: The landing page user reaches; if enabled, PMax can use URL expansion to find new, relevant landing pages.