Google Merchant Center Custom Labels Strategy

What Custom Labels Are For

Custom labels (custom_label_0 through custom_label_4) let you add your own categorization data to products in your feed. Unlike Google's predefined attributes (category, brand, condition), custom labels are entirely yours: you define what values mean what. Once assigned, you can use custom labels in Google Ads to create product groups, which lets you bid differently or run separate campaigns for different product segments.

A Five-Label Framework

With five label slots, a systematic framework works better than ad hoc assignment. One common approach: custom_label_0 for margin tier (high, medium, low), custom_label_1 for seasonality (evergreen, seasonal, clearance), custom_label_2 for bestseller status (top_seller, average, slow_mover), custom_label_3 for promotion status (on_sale, full_price, bundle), custom_label_4 for product lifecycle (new_arrival, established, end_of_life). With this framework, any combination of labels creates a precise product group you can bid on independently.

Practical Example: Bidding by Margin

Products with high margin can sustain higher CPCs in Shopping campaigns. Products with low margin need lower CPCs or they become unprofitable. Without custom labels, you cannot bid differently by margin unless you build separate campaigns for each margin tier. With custom_label_0 set to high, medium, or low margin, you create three product groups in Google Ads and set bids accordingly. High margin products get aggressive bids; low margin products get conservative bids.

How to Add Custom Labels

Custom labels must be added to your product feed, either in the primary feed or via a supplemental feed. In a Google Sheet feed, add columns named custom_label_0, custom_label_1, etc. and populate them with your values. Values must be consistent strings: "high" not "High" not "HIGH." Case sensitivity matters because Google Ads uses exact string matching when creating product group filters.