What Is a Product Feed?

Google's product data specification names the fields it will not do without: id, title, description, link, image link, availability and price. Availability has to be one of in stock, out of stock, preorder or backorder. Price has to carry a currency in the standard ISO 4217 format.

There are limits on the fields too. An id runs to 50 characters, a title to 150, a description to 5,000. Titles are the one worth caring about, because in Shopping the title is doing the job a keyword does in Search.

Brand is listed as optional but required for new products, apart from movies, books and musical recordings, and it is capped at 70 characters. GTIN is strongly recommended when your product has one. MPN is only required when a product has no manufacturer-assigned GTIN. Condition is only required when the item is used or refurbished.

Read that list again and notice what it means in practice. Plenty of disapprovals come down to a field somebody read as optional. Google's specification says accurate, correctly formatted data is what prevents disapprovals and display problems, and it means it literally.

Scaley AI is our own product, and it works on top of a feed that already exists. It tags every SKU by margin and velocity, pushes those tags into your Merchant Center custom labels every day, and calls out the products losing you money. It prepares each change with the reason attached and writes nothing to your account until you approve it. It does not watch your disapprovals - Merchant Center already does that, and we leave it there.

We are not a feed tool and we do not pretend to be. If you need to remap and rewrite attributes for several channels in one place, buy a feed management platform. DataFeedWatch calls itself exactly that, and says it connects to more than 2,000 channels and marketplaces.

And on a small catalogue, do it yourself. A few dozen products, an afternoon, and titles written by somebody who knows the products will beat anything automated. Software earns its keep when there are more SKUs than you can hold in your head.

A supplemental feed, which Google now calls a supplemental data source, is a second file that adds to or fixes data in your main feed. Google's words: it provides more details or updates existing details that may be missing from your primary data source.

It has one hard limit. Google says a supplemental data source can't be used to add or remove products, or used on its own. Only the main feed, the primary data source, can do that. So a supplemental feed is a patch, not a catalogue.

That makes it perfect for the jobs your shop platform will not do. Better titles for your top sellers. Custom labels for margin. A missing GTIN or product type. You change the patch without touching the main feed your store generates.

In Merchant Center, the supplemental sources tab only shows once you switch on the Advanced data source management add-on in settings. Then add a supplemental source, either from a file or from Google's Sheets template.

The sheet needs one column that matters more than the rest: id. Google says to match your product ID from the main feed exactly. Then add one column per attribute you want to set, like title or custom_label_0. Each row is one product. Any product ID that does not match a product in the main feed does nothing.

A Google Sheet is the easiest way for a small team, because anyone can edit a title without touching the store.

Work through it in the order that moves money.

Titles first. Put the words people search at the front: product type, brand, the key attribute, size or colour. Shopping has no keywords, so the title decides which searches you can show for.

Then the identifiers. Fill GTIN and brand wherever the product has them. They help Google match the product to the right searches and avoid disapprovals.

Then images. A clean, true photo of the exact product, no text or watermark on it.

Then product type and Google product category, so the product sits in the right place.

Last, custom labels. Tag products by margin and sales speed so campaigns can bid on profit. Google allows five, custom_label_0 to custom_label_4, and shoppers never see them.

Most store platforms build the main feed for you. Shopify and WooCommerce both have Google apps that sync your products to Merchant Center and keep price and stock up to date. Start there.

What those apps do not do well is the extra work: rewriting titles for search, adding margin labels, fixing one product without changing it in the store. That is the job for a supplemental feed, or for a feed management platform if you sell on many channels.