How do I track free product listing revenue separately from paid Shopping in Google Analytics 4?
Free product listing clicks from Google Merchant Centre arrive in GA4 as direct traffic or `google / organic` by default because no UTM parameters are attached to the product URLs submitted in the feed. To track free listing revenue separately, you add UTM parameters to the product landing page URLs in the GMC feed — for example, `utm_source=google&utm_medium=free-listing&utm_campaign=shopping-free` — and then create a custom channel group in GA4 that recognises this source/medium as a distinct channel called "Free Product Listings". Once set up, the GA4 Acquisition report will show free listing sessions, transactions, and revenue as a separate line item, distinct from both paid Shopping (which uses auto-tagging) and standard organic search (which uses `google / organic` without the custom UTM).
What is a supplemental feed and how is it different from the primary product feed?
The primary product feed is the main data source submitted to Google Merchant Centre — for most US Shopify brands, this is the feed generated by Shopify's Google Sales Channel. A supplemental feed is a secondary data source that overrides or adds attributes to the primary feed without replacing it. The supplemental feed does not need to contain all product data — it only needs to contain the product ID and the attributes you want to change or add. A supplemental feed with a `title` column rewrites Shopping titles without touching Shopify. A supplemental feed with `custom_label_0` through `custom_label_4` columns injects campaign segmentation labels. A supplemental feed with a `gtin` column adds barcodes for branded products. The supplemental feed and primary feed are both connected to the same GMC account, and GMC merges them at the product level.
What is the best feed management tool for a US Shopify store — Feedonomics, DataFeedWatch, or GoDataFeed?
Each tool suits different scale and complexity needs. Feedonomics is the most capable tool for large catalogues (10,000+ SKUs) and complex multi-channel feed requirements — it has the most sophisticated transformation rules and the strongest customer support, but it is the most expensive option and has a steeper learning curve. DataFeedWatch is strong for mid-sized catalogues (500 to 10,000 SKUs) and is the most commonly used tool for Shopify brands running Google and Meta feeds simultaneously — it has a straightforward interface and solid Shopify integration. GoDataFeed is a simpler option for smaller catalogues that need basic title optimisation and custom label injection without the full rule-based logic of Feedonomics. For most US Shopify brands running PMax with catalogues under 5,000 SKUs, DataFeedWatch covers the majority of supplemental feed use cases at a reasonable cost.
What GTINs are required in a Google Merchant Centre feed for US products?
US products sold by branded manufacturers — products that have a UPC barcode — must include the correct UPC (12-digit) or EAN (13-digit) in the `gtin` attribute of the feed. This applies to any product that a manufacturer assigns a barcode to, including products you stock and resell. Custom-made, handmade, or one-of-a-kind products that have never been assigned a manufacturer barcode must set `identifier_exists: false` in the feed. Products where you know the GTIN exists but do not have it on hand should not set `identifier_exists: false` — the correct action is to source the GTIN from the manufacturer or GS1 database. Stocked branded products submitted without a GTIN receive reduced impression share in Shopping, but are not typically disapproved unless the `identifier_exists: false` attribute is explicitly set to false on a product that does have a known GTIN.
How do I set up Merchant Centre Promotions to show sale badges in US Google Shopping ads?
Merchant Centre Promotions allow you to add a "sale" or promotional overlay badge to Shopping ads during promotions. To set them up in the US, navigate to the "Promotions" section in Google Merchant Centre, click "Create promotion", and fill in the promotion details: promotion title (displayed to buyers), discount type (percent off, amount off, or free shipping), start and end dates, and either an all-products scope or a specific product filter using product IDs, brands, or custom labels. Promotions require approval from Google before they go live — approval typically takes one to three business days. For sale events with a start date, submit the promotion at least three business days in advance. Promotions can also be managed via a promotions feed for catalogues with many simultaneous promotions, which allows bulk promotion creation and scheduling in a structured data file.
