Performance Max vs Standard Shopping: how your feed affects both

Performance Max (PMax) campaigns generate heated debate in PPC. But one thing is rarely discussed: how the same product feed behaves differently in PMax versus Standard Shopping, and what to optimise accordingly.

What they share

Both campaign types draw from the same product data in Google Merchant Center. There's no separate PMax feed — your Merchant Center catalogue powers both simultaneously. Improvements to your feed benefit both immediately.

Where they differ: how Google uses your data

Standard Shopping uses your product title, description, and google_product_category primarily for keyword-based query matching. Title optimisation — adding brand, attributes, size, colour — has a direct, measurable impact on impression share.

Performance Max blends feed data with audience intelligence, creative assets, and cross-channel inventory. PMax generates ad creative automatically across Search, Shopping, YouTube, Display, Discover, and Gmail.

For PMax specifically: image quality matters more (images appear at large display sizes in YouTube and Display formats), description quality matters more (PMax uses descriptions for ad copy across multiple formats), and title keyword density matters less.

Custom labels: more important in PMax

In Standard Shopping, custom labels enable bid segmentation. In PMax, they enable asset group segmentation. Create separate PMax asset groups for different product segments, each with tailored creative assets and bidding. A "hero products" label, a "seasonal" label, and a "clearance" label let you run completely different PMax strategies for each.

Product type: the PMax grouping field

Your product_type field is particularly valuable for PMax. Clean, hierarchical product_type values (Mens > Jackets > Waxed Jackets) give PMax useful category context for its machine learning. Inconsistent values deprive PMax of one of its most useful grouping signals.

If PMax is treating all your products as one undifferentiated pool, the most likely cause is missing or inconsistent product_type and custom_label data in your feed.

PMax feed optimisation checklist

• ✅ Titles: factual, descriptive, include brand and key attributes
• ✅ Descriptions: minimum 150 words, factual, include key specs and use cases
• ✅ Images: high quality, min 1200px wide for PMax Display placements
• ✅ Custom labels: segmented by margin tier, seasonality, bestseller status
• ✅ Product type: clean hierarchy, consistent across catalogue
• ✅ GTINs: complete coverage for branded products