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Shopping Feeds and the Google Merchant Center

Redaktion ·

Shopping Feeds and the Google Merchant Center

In classic search campaigns the keyword decides when an ad runs. In Shopping and Performance Max there are no keywords. Instead, the product feed decides. Google reads the attributes of your products and matches them against search queries on its own. That means: your feed is your campaign control. If it is poor, no amount of bidding will save it — the delivery simply will not fit.

This article explains what the feed is, which attributes matter, where the biggest optimization lever sits, and why the Merchant Center disapproves products.

The Product Feed Replaces Keywords

The product feed is a structured list of all your products with their properties, which you upload to the Google Merchant Center. From this data Google builds the Shopping ad and decides which search queries it is relevant for.

Because there is no keyword targeting, the field content is the targeting. If your title contains the word running shoe, Google can show your product for the search men’s running shoes. If the term is missing, the chance is missing. This is exactly why feed optimization in Shopping is what keyword research is for text ads.

The differences between the campaign types are covered in the glossary entries on Shopping campaign and Standard Shopping vs. Performance Max.

The Required and Important Attributes

Google defines required attributes in the product data specification (accessed 2026-06-06), without which a product will not be served:

  • id — unique product identifier (max 50 characters).
  • title — product name (max 150 characters).
  • description — product description (max 5000 characters).
  • link — product page URL.
  • image_link — URL of the main image.
  • availability — stock status (in_stock, out_of_stock, preorder, backorder).
  • price — price in ISO 4217 format.

On top of these come important recommended attributes that strongly influence data quality and therefore performance:

  • gtin — Global Trade Item Number (EAN/UPC/ISBN). Strongly recommended if available. Only provide a GTIN if you’re sure it is correct.
  • mpn — manufacturer part number, required if no GTIN exists.
  • brand — brand, required for new products.
  • google_product_category — Google’s product category (from the official taxonomy).
  • product_type — your own categorization (max 750 characters), useful for campaign structure.
  • condition — required only for used or refurbished goods.

Title and Description Are the Biggest Lever

Because the feed replaces keywords, the product title is the single most important field. The most important terms belong at the front: what users are likely to search should sit in the first third of the title. A good structure is brand + product type + key attributes (color, size, model).

Google demands accuracy here: the title must accurately describe the product and match the title on the landing page. Prohibited are promotional text like free shipping, all capital letters, or gimmicky foreign characters. The same rules apply to the description — it should deliver product information, no advertising, no links, no competitor references.

In practice this means: optimize title and description like snippets, not like advertising slogans. More relevant, correct terms at the front means more matching search queries.

Custom Labels for Campaign Control

Custom labels (0 to 4) are up to five freely definable fields that have nothing to do with how the product is displayed — they serve only you. You use them to group products for bidding and reporting.

Typical uses:

  • Margin — high/medium/low margin, to promote top sellers more aggressively.
  • Season — summer/winter items for seasonal control.
  • Performance — bestsellers vs. slow movers.
  • Price tier — to steer premium and entry-level products separately.

In Standard Shopping you can split campaigns or ad groups by custom labels and set different bids. In Performance Max you use them to structure asset groups or to delimit, via label, which products even flow into which campaign.

Supplemental Feeds

A supplemental feed does not replace the whole feed but supplements or overrides individual fields in the primary feed — linked via the id. This is useful when the main feed comes from the shop system and you do not want to maintain every field there.

Typical cases: adding custom labels after the fact, supplying a missing google_product_category, overriding titles for certain products, or backfilling GTINs. The supplemental feed keeps the primary feed clean and separates the marketing logic from the pure master data.

Common Disapproval Reasons

The Merchant Center disapproves products when data quality is not right (source: Google Merchant Center Help, accessed 2026-06-06). The most common causes:

  • Price mismatch. The price in the feed differs from the price on the landing page that Google loads. This leads to preemptive disapproval of the item. Most common cause: caching, currency, or gross/net differences.
  • GTIN problems. An incorrect GTIN (often accidentally taken from another product) or a GTIN that does not match the stated brand. Both depress performance or lead to disapproval.
  • Missing required attributes. If price, availability, image_link, or another required field is missing, the product is not served.
  • Prohibited title/description content. Promotional text, capitalization, or special characters violate the specification.
  • Availability mismatch. The feed says in_stock, the page shows sold out — this also triggers disapproval.

The logic behind it: Google wants the ad to match the destination page exactly. Any discrepancy between feed and landing page is a reason for disapproval.

Connection to Performance Max

In Performance Max the feed is even more central. PMax draws from the Merchant Center and combines the product data with your asset groups to serve across all Google channels. Since PMax allows little manual control, feed quality is one of the few genuine levers you retain. Custom labels and clean attributes are your most important steering instrument in PMax.

How to position Performance Max overall is covered in the lexicon entry on understanding Performance Max.

FAQ

Why does the feed replace keywords in Shopping?

Because Shopping and PMax campaigns have no keyword targeting. Google reads the product attributes and matches them against search queries on its own. What is not in the feed — especially in the title — cannot be served.

Which fields are required in the product feed?

Required are id, title, description, link, image_link, availability, and price. Strongly recommended are GTIN, MPN, brand, google_product_category, and product_type — without them data quality and therefore performance suffer.

How do I optimize the product title?

Put the most important search terms at the front, with the structure brand plus product type plus key attributes. The title must be accurate and match the landing page. Prohibited are promotional text, all capital letters, and gimmicky special characters.

Why is my product disapproved in the Merchant Center?

The most common reasons are a price mismatch between feed and landing page, an incorrect GTIN or one that does not match the brand, missing required attributes, or prohibited title content. Google requires that feed and destination page match exactly.

What are custom labels good for?

Custom labels group products for bidding and reporting — by margin, season, or performance, for example. They do not affect the ad itself but let you structure campaigns and asset groups sensibly.

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