Hi {First name of your developer},

A click on one of our ads doesn’t always result in the purchase of the exact product that was advertised. Conversions with Cart Data allows us to see which products are actually purchased after an ad click, which items convert most often, and which products are our top sellers.

This feature provides valuable insights for optimization and reporting, and I’d love to get it working. To do so, I’ll need your help on the development side. Below is a short but detailed briefing explaining what needs to be implemented.

1. Extend the Data Layer With Cart Data Parameters

The data layer on the {insert URL page or event name} (typically the purchase or order-confirmation event/page) needs to be extended with Cart Data parameters.

These parameters are an addition to our existing conversion tracking data layer and must dynamically pass information about the products included in a conversion. This enables Google Ads to associate purchased items with ad clicks.

You can find the full list of required parameters in Google’s documentation here:
https://support.google.com/google-ads/answer/9028614

Example: Data Layer Implementation

Below is a sample implementation showing how the Cart Data parameters should be added to the existing purchase data layer push.

<!– Sample Code: Data Layer Push –>

dataLayer.push({

  “event”: “purchase”,

  “transaction_id”: “556t1545c3c”,

  “value”: 50,

  “currency”: “USD”,

  <!– Start Conversions with Cart Data parameters –>

  “discount”: 150,

  “aw_merchant_id”: 987665445,

  “aw_feed_country”: “US”,

  “aw_feed_language”: “EN”,

  “items”: [

    {

      “id”: “126345”,

      “quantity”: 2,

      “price”: 170

    },

    {

      “id”: “67654890”,

      “quantity”: 11,

      “price”: 35.00

    }

  ]

  <!– End Conversions with Cart Data parameters –>

});

Static vs. Dynamic Parameters

Static Parameters

The following fields can be implemented as static values:

• aw_merchant_id: {Insert your Google Merchant Center ID}
• aw_feed_country: {Insert feed country}
• aw_feed_language: {Insert feed language}

In most cases, advertisers only operate in one country, so static values are sufficient.

Dynamic Parameters

All other fields must be populated dynamically:

• transaction_id
• value
• currency
• discount
• items[]

Each purchased product must be included in the items array with:

• id – Use the {internal ID field used in GMC (e.g. SKU or MPN)} so it matches Google Merchant Center
• price – Item price
• quantity – Quantity purchased

Multi-Country / Multi-Language Setup (If Applicable)

If we advertise in multiple countries or languages, please make the following parameters dynamic based on the shipping country or site language:

• aw_feed_country
• aw_feed_language

Example Logic

• Use US for both aw_feed_country and aw_feed_language if the shipping country is the United States.
• Use GB for aw_feed_country if the shipping country is the United Kingdom, and EN for aw_feed_language if the website language is English.

2. Google Ads Conversion Tags

Once these Cart Data variables are available in the data layer, I can configure the Google Ads conversion tags in Google Tag Manager to send this information to Google Ads.

No changes are needed on your side for GTM—just let me know once the data layer implementation is complete, and I’ll take it from there.

If you have any questions or need clarification while implementing this, feel free to reach out.

Best regards,
{Your name}

Official Google Resource:
https://support.google.com/google-ads/answer/9028614