Google Ads and feed rules - supplementing your product data without rebuilding the feed

Feed rules are transformation functions applied to your product data between your source feed and how it appears to Google's systems. They let you add, modify, or override attributes at scale without touching the underlying feed. For businesses where the feed is generated automatically from an ecommerce platform and is difficult to modify, feed rules are the practical path to feed optimisation.

The most common use cases

Improving product titles is the most valuable application. If your source feed generates titles like "SKU-12345 Blue Medium" and you want Google to see "Nike Air Force 1 Low Men's Trainers White Size 10 UK", a feed rule can reconstruct the title from multiple feed attributes - brand, product type, colour, size - without touching the source data. The rule combines existing attributes in a new format and overwrites the title field Google sees.

Appending custom labels based on existing data is another high-value use. If your feed includes a margin field, a feed rule can map margin ranges to custom label values - Label 0 = high margin, Label 1 = mid margin, Label 2 = low margin - enabling campaign segmentation by margin without any developer work. Similarly, mapping seasonal category indicators, clearance flags, or new arrival tags from existing feed data to custom labels enables sophisticated campaign structures based purely on feed rule logic.

Fixing common disapproval issues

Feed rules can fix some categories of product disapproval without waiting for feed updates. If products are disapproved because a required attribute is missing or formatted incorrectly, a rule that provides a default value or reformats an existing value can resolve the disapproval immediately. This is particularly useful for missing GTIN handling - a rule that sets identifier_exists to false for products where no GTIN is available tells Google explicitly that no barcode exists rather than leaving the field blank, which avoids a common disapproval category.

Rules have limits

Feed rules cannot add information that does not exist anywhere in your feed. If a required attribute - like price or availability - is missing from your source data, a rule cannot create it from nothing. Rules transform and combine existing data - they do not generate new data. Understanding this boundary prevents frustration when rules cannot solve problems that require changes to the underlying feed.