Custom labels are five optional Merchant Center feed attributes, custom_label_0 through custom_label_4, that hold values the advertiser defines, such as margin, season, or bestseller status. They are not shown to shoppers and are used to subdivide products into listing groups in Shopping and Performance Max campaigns.
Key Takeaways
- Five label slots per product, numbered 0 to 4
- Values are yours to define; Google does not interpret them
- Shoppers never see them
- Used to split products into listing groups with different bids, budgets, or targets
- Labels only help if the values are kept current
What Are Custom Labels
The standard feed attributes describe the product: brand, category, price. Custom labels describe what the product means to your business. Typical uses are profit margin bands, seasonality, price tiers, clearance stock, or new arrivals.
How It Works
Each label is a column in the Merchant Center feed. You fill it per product, either in the source file or with feed rules in Merchant Center. In a Shopping campaign you subdivide product groups by a label; in Performance Max you use labels to define the listing groups of an asset group, or to split products across campaigns with different targets.
Practical Example
A retailer sets custom_label_0 to “high-margin” or “low-margin”. It then runs two Performance Max campaigns: one for high-margin products with a lower Target ROAS, allowing more spend, and one for low-margin products with a stricter target. Without the label, both sets would compete under a single target that suits neither.
Why It Matters
Google optimizes toward the conversion value it sees, not toward profit or stock levels. Custom labels are the main way to bring business priorities that live outside Google Ads into how product campaigns are structured. Stale labels, such as a “season” value never updated, quietly misdirect budget.