Have you ever wondered “Why did someone who searched for pool floaties click on my ad for bedroom curtains?” Reliance on Google Merchant Center’s primary feeds could be the culprit, and supplemental feeds can be your solution.

In essence, Google Merchant Center has two types of feeds that you can take advantage of: primary and secondary. The primary feed is required for Google Merchant Center – it’s where you submit the core product data for Shopping ads. The supplemental feed is optional and allows you to overwrite or supplement any existing primary feed data.

Why Would I Need a Supplemental Feed?

Most primary feeds contain only basic data, the bare minimum required to get your ads up on the Google Shopping Network. Supplemental feeds are used to improve listings by adding new or corrected information to primary feeds to strengthen Shopping campaign performance.

Supplemental feeds allow you to include more than 50 different pieces of information in your Shopping ads. That sends Google better algorithmic relevance signals, enabling stronger search relevance, better targeting, less wasted spend, and increased campaign performance.

The guidelines for Shopping ads data vary by industry, but Google requires these columns for all primary feeds:

  • id
  • title
  • description
  • link
  • image_link
  • availability
  • price
  • brand
  • gtin or mpn
  • condition

That means that 10 data points distinguish one product from another. It’s best not to rely on primary feed data if you’re in a competitive field. With more than 50 to choose from, we can do much more to set our Shopping listings apart in a supplemental feed.

You might use supplemental feeds if:

  • Your titles are missing important information like brand, size, or color.
  • Your feed contains fewer than the recommended five product types.
  • You need to add promotion IDs to specific products.
  • You want to add custom labels based on seasonality, price ranges or best-selling identifiers.

What Should I Change with Supplemental Feeds?

Supplemental feeds allow you to add or change anything in your primary feed. Mainly they’re used to add information, but they can also be used to replace titles, descriptions, and more.

For example, let’s say that your product’s title is “MAX Torch 4 US 10 Men’s Running Shoe – Nike.” You could use a supplemental feed to rearrange the product title in Shopping without having to modify what it looks like on your website. You could move the brand to the front and add the color, like this: “Nike Men’s MAX Torch 4 Running Shoes – Black/Gray – US Size 10.”

Or you could add custom labels and promotion IDs. These can be very useful when segmenting your shopping campaigns by custom groupings, either by style, sales items, best sellers, or just fine tuning the groupings. For the example above, we could add the following information into our supplemental feed:

Custom labels can be used to segment your Shopping campaigns into fine-tuned groupings to better optimize your shopping performance. This is very useful when using Smart Bidding on your Shopping campaigns – for example, you could segment your best sellers using a custom label like the one in the example above.Promotion IDs are used with corresponding promotions that are have to be entered in Google Merchant Center under the Marketing and Promotions tabs. They specify a sale or promotion code that makes your product stand out in the Shopping listings, such as free shipping.

How Do I Create a Supplemental Feed?

If you uploaded your feed via file upload, you already have the data to get started. Just download the primary feed that you are using. If your feed was imported via your website platform and is locked by a Content API, and if you have a Microsoft Ads account connected to Google Merchant Center, you can download your feed from Microsoft Ads.

The following six steps describe how to turn your primary feed data into the supplemental feed you need in order to improve your Shopping ads.

  1. Create. Put your Primary Feed into a new Google Sheet. This will be your supplemental feed.
  2. Modify. Insert the needed columns into your supplemental feed Google Sheet. You can download a full template from Google’s servers here (.zip file) if you need it.
  3. Fill in. Insert your supplemental product information into the new, blank columns in your Google Sheet.
  4. Remove. Delete all of the columns from your supplemental feed in your Google Sheet that have not changed from the primary feed – except the ID column. IDs must remain in the supplemental feed so that they can match to the same products in the primary feed. Other than IDs, you only want to include new or changed data in the supplemental feed. You do not want to overwrite data with the same data, because it may become outdated. Delete columns where nothing has changed from the primary feed, and delete data from cells that do not need to be changed. Only include data in the supplemental feed that needs to be added to or overwritten in the primary feed.
  5. Submit. When your supplemental feed is complete, submit it in Google Merchant Center to optimize your Shopping listings.
    • In Google Merchant Center, select Feeds from the Products tab.
    • Then click “Add Supplemental Feed,” as shown below. This link may appear as a plus sign in older versions of Google Merchant Center.
    • Fill in a supplemental feed name and make sure that the “Google Sheets” option is checked. The example below shows a feed name of “Supp Feed.”
    • Check “Select an existing Google spreadsheet” which will open a pop up window asking you to link to the supplemental feed you created. You can also create an upload schedule at this point if you plan to update your supplemental feed Google Sheet frequently.
    • Lastly do not check the box for you primary feed, as it will make this supplemental feed the main source for data instead of a secondary data source. As shown below, the options indicated in red should not be checked. Click the blue Continue button, and you’re done!
  6. Test. Double check that your supplemental feed is being used for your Shopping ads. To do this, click on your primary feed and click on the Feed Rules tab. You should see something similar to one of the two images below, image A or B.
    If your screen looks like the one labeled (A) on the top, everything is fine. If it looks like the one labeled (B) on the bottom, you need to follow the steps below to associate the supplemental feed with the rule.
    Click on the rule for all attributes and click “Add Source,” as shown above marked (C). Then, as shown in the step marked (D), choose the supplementary feed name – here called “Supp Feed” – as the one to take from if there is no attribute in the primary feed. When you’re finished, it should look like the one marked (E) does. Save the draft by clicking the blue button.
    Lastly, as shown in the image above, you will see an option to apply your changes, discard them, or test them. If you are unsure of the changes you made, test them first before applying them.

If you use the Google import feature in Microsoft Ads, all of the changes and additions to the supplemental feed that you upload to Google Merchant Center will also be in your Microsoft Shopping ads.

Supplemental feeds are an extremely helpful tool for adding or improving information in your primary feed data. The use of Google Sheets makes this incredibly easy to do, and changes can be made in real time.