Supplemental feed label

A supplemental feed label is this glossary’s name for a custom label whose value is supplied by a Merchant Center supplemental data source.

By Berend Vrakking, founder of Product Metrics. Updated 28 October 2026.

Supplemental feed label example

Adding a performance group
Field	Value
Existing product ID	shoe-001
Custom label field	custom_label_0
Supplemental value	stars

The matched product keeps its primary product data while receiving a group value for campaign organisation. Illustrative data.

Put it into practice

Explore it: Product SegmentationTurn approved groups into Merchant Center labels.
Read the guide: Optimise Google Shopping adsConnect product data and campaign management.

Supplemental feed label: one product and the whole account

The label belongs to the matched product. Products with the same value can be grouped in campaign reporting or configuration. Check matching and source rules before relying on the group; a label on the wrong item changes its meaning.

Custom labels can describe margin bands, seasonality or performance groups. Product Metrics uses approved Merchant Center labels to carry segmentation into configured campaigns. Keep the label meaning consistent across your products.

Supplemental feed label: common mistake

Treating this as a Google term or confusing it with Merchant Center feed labels. Google’s feature is the supplemental data source, which can add or override custom labels for products that already exist in a primary source.

Supplemental feed label: questions

Is this a separate Google attribute?

No. Google has no attribute called a supplemental feed label. The term describes a custom label, one of the five attributes custom_label_0 to custom_label_4, whose value comes from a supplemental data source. Google’s own wording is supplemental data source, and feed labels are a separate Merchant Center setting.

Does adding a label change campaign priorities?

No, not by itself. A label only changes how products are grouped. Campaign priorities change only when your campaign configuration splits on that label, for example in Standard Shopping product groups or listing groups within Performance Max asset groups. Supplying the label data does not define your advertising strategy, so you set the priorities yourself.

Sources

Google Merchant Center Help: Create a product data source

Keep reading

Custom labelsUnderstand the product attributes being populated.
Supplemental feedUnderstand the source that adds the label.