custom_label_0 to custom_label_4
The five custom_label attributes in Merchant Center, free-form buckets for tagging products by margin, price, season, lifecycle or bestseller status, and how they drive campaign segmentation in Google Ads.
Custom labels are five free-form tags you attach to each product. Google does nothing with them itself; they exist purely so you can slice your catalogue in Google Ads and bid differently on different groups. The common uses are margin band, price tier, season, product lifecycle and bestseller status, so you can spend more where it pays and less where it doesn't.
What custom labels are
| Attribute | What it is | Example |
|---|---|---|
custom_label_0 |
A free-form tag, dimension 1 | high_margin |
custom_label_1 |
A free-form tag, dimension 2 | bestseller |
custom_label_2 |
A free-form tag, dimension 3 | AW26 |
custom_label_3 |
A free-form tag, dimension 4 | clearance |
custom_label_4 |
A free-form tag, dimension 5 | price_over_100 |
Five free-text fields per product, custom_label_0 to custom_label_4. Google reads them but doesn't act on them: they change nothing about how a product matches or ranks. Their entire purpose is downstream, in Google Ads, where they become dimensions you can subdivide product groups by and bid on differently.
The five common schemes
Each label should hold one dimension, applied consistently. The usual five:
- Margin band:
high_margin/mid_margin/low_margin. Bid up where you keep more of the sale. - Price tier:
price_under_25/price_25_100/price_over_100. Price bands often want different tROAS targets. - Season:
SS26/AW26/all_year. Push seasonal stock in its window, ease off out of season. - Lifecycle:
new/core/clearance. New products may need incubation; clearance wants volume. - Performance:
bestseller/steady/slow_mover. Concentrate spend where it converts.
You don't have to use all five, and you can choose different dimensions to suit your business: but the discipline is the same: one dimension per label, a small tidy value set, applied the same way across every product.
How they drive campaign segmentation
In Google Ads, custom labels are a subdivision dimension for product groups (alongside product_type, brand and category). That lets you:
- Split a campaign by margin, season or lifecycle and set a different bid or tROAS target for each slice.
- Isolate a group into its own campaign: e.g. a clearance campaign chasing volume, separate from a bestseller campaign defending position.
- Report cleanly on how each slice performs, which is the raw material for the next round of bidding decisions.
This is the natural partner to google_product_category vs product_type: category tells Google what the product is; custom labels tell your campaigns how to treat it. For the full segmentation playbook, see custom labels and campaign segmentation.
Deep dive Keeping labels clean enough to bid on
Custom labels are free-form, which is their strength and their trap. A label scheme is only useful if it's consistent: and consistency is exactly what erodes when several people, or several feed rules, touch the same field over time:
- One dimension per label, always. The moment
custom_label_0holdshigh_marginon some products andAW26on others, you can no longer build a clean product group on it. Pick the dimension per label and never mix. - A small, closed value set.
bestsellerandbest-sellerandBestsellerare three different values to Google Ads: they won't group together. Decide the exact tokens and enforce them. - Derived from real data, kept current. A margin label baked in once and never refreshed lies within a season. Labels that track live facts (this quarter's margin, current stock age, actual bestseller status) are the ones worth bidding on. Stale labels quietly misdirect spend.
- Watch the invisible-layer trap. Labels set by a feed rule live only inside Merchant Center and are easy to forget; two rules editing the same label months apart create values nobody designed. If labels are doing real segmentation work, they belong in a layer that's inspectable per product, not scattered across a rules tab.
Get this right and custom labels become the lever that lets BidSmart's approval-first bid recommendations act on the slices that matter: spend concentrated on high-margin bestsellers, eased off slow-moving low-margin stock. Get it sloppy and the labels are just noise.
How this works in /tools
Enrichment can derive custom labels from real catalogue data (margin band, price tier, seasonality, lifecycle and performance) as consistent, closed-value tags written to a supplemental layer, kept current as the underlying facts change, and never overwriting anything your store already sets. Clean labels are what let campaign segmentation and BidSmart's bid recommendations act on the right slices of the catalogue. For the enrichment workflow, see custom labels in Optimise; for turning labels into campaign structure, see custom labels and campaign segmentation.
Frequently asked questions
Does Google use custom labels to place my products?
No. Custom labels have no effect on matching or ranking, since Google ignores them for serving. They exist solely for you, to subdivide and bid on product groups inside Google Ads. That's also what makes them safe to experiment with.
How many labels can I use and what values are allowed?
Five, custom_label_0 through custom_label_4, each holding one free-text value per product. Keep each label to a single, consistent dimension (one for margin, one for season, and so on), with a small, tidy set of values so your campaign structure stays clean.
What should each label represent?
Pick one dimension per label. Common choices are margin band, price tier, seasonality, product lifecycle (new/core/clearance) and performance (bestseller/slow-mover). Decide the scheme once and apply it consistently across the catalogue.