Enhanced Conversions help Google Ads recover conversion attribution lost due to privacy restrictions or third-party cookie limitations by sending hashed first-party customer data (e.g., email, phone, name) directly to Google. In osCommerce, implementing this via Google Tag Manager (GTM) ensures flexibility, privacy compliance, and minimal code repetition.

🎯 Why Use Enhanced Conversions?

• Improves attribution accuracy
• Boosts match rates for conversions (especially on iOS/Safari)
• Supports smart bidding & remarketing effectiveness
• Works with both standard and server-side GTM setups

✅ Prerequisites

• Google Ads Conversion Action already created
• GTM installed on all osCommerce pages
• checkout_success.php editable
• Customer data (email, phone, etc.) available on order confirmation
• GDPR/CCPA consent compliance in place (where applicable)

🧾 Step 1: Push Customer Data into the Data Layer (on Purchase)

In your checkout_success.php file, inject the customer data securely:

✅ PHP + JavaScript Example:

<?php
$order = getOrderDetails($order_id);
?>

<script>
window.dataLayer = window.dataLayer || [];
dataLayer.push({
  event: 'purchase',
  transaction_id: '<?= $order['id'] ?>',
  value: <?= $order['total'] ?>,
  currency: 'USD',
  user_data: {
    email: "<?= $order['customer_email'] ?>",
    phone_number: "<?= $order['customer_phone'] ?>",
    first_name: "<?= $order['customer_firstname'] ?>",
    last_name: "<?= $order['customer_lastname'] ?>",
    address: {
      street: "<?= $order['customer_address'] ?>",
      city: "<?= $order['customer_city'] ?>",
      region: "<?= $order['customer_state'] ?>",
      postal_code: "<?= $order['customer_zip'] ?>",
      country: "<?= $order['customer_country'] ?>"
    }
  }
});
</script>

⚠️ Ensure that this is done only after explicit user consent where required.

🏷️ Step 2: Create Data Layer Variables in GTM

Go to Variables → New → Data Layer Variable. Create the following:

Variable Name	Data Layer Variable Name
DL - email	user_data.email
DL - phone_number	user_data.phone_number
DL - first_name	user_data.first_name
DL - last_name	user_data.last_name
DL - address_street	user_data.address.street
DL - address_city	user_data.address.city
DL - address_region	user_data.address.region
DL - address_postal_code	user_data.address.postal_code
DL - address_country	user_data.address.country

🔧 Step 3: Create the Google Ads Conversion Tag with Enhanced Conversions

1. Go to Tags → New
2. Choose Google Ads Conversion Tracking
3. Enter your Conversion ID and Label
4. Click “Include Enhanced Conversions”
5. Select: “Use data layer”
6. Map the variables:

Enhanced Field	GTM Variable
Email	{{DL - email}}
Phone Number	{{DL - phone_number}}
First Name	{{DL - first_name}}
Last Name	{{DL - last_name}}
Street Address	{{DL - address_street}}
City	{{DL - address_city}}
Region	{{DL - address_region}}
Postal Code	{{DL - address_postal_code}}
Country	{{DL - address_country}}

7. In the tag’s Conversion Value, use:
   • {{DL - value}} (set this up as a DL variable too)
8. Trigger: Use a Custom Event Trigger for purchase

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🔍 Step 4: Configure Trigger for Purchase Event

1. Go to Triggers → New
2. Choose: Custom Event
3. Event name: purchase
4. Name it: Trigger - Purchase Event

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🧪 Step 5: Test the Enhanced Conversion Setup

✅ Use GTM Preview:

• Navigate to the thank-you page
• Ensure:
  • purchase event is pushed
  • Google Ads Conversion tag fires

✅ Use Google’s Enhanced Conversions Helper:

• Go to: https://ads.google.com/aw/conversions/ec/setup
• Validate whether enhanced data is passing

✅ Chrome DevTools Check:

• Open Network tab → XHR
• Look for request to googleads.g.doubleclick.net
• Check payload includes hashed values (e.g., em, ph)

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🔐 Step 6: Privacy & Consent Considerations

To be GDPR/CCPA-compliant:

• Only push user_data to the data layer after user consent
• Use a Consent Management Platform (CMP) with GTM (e.g., Cookiebot, OneTrust)
• Integrate with Consent Mode v2 in Google

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🧠 Pro Tips for osCommerce Integration

Tip	Benefit
Hash data before pushing to GTM (optional)	Adds extra privacy on frontend
Combine with GA4 purchase tracking	One tag → multiple destinations
Implement via GTM Server-Side	Even higher attribution & privacy control

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✅ Summary

With this setup, you now have:

• ✅ Accurate Google Ads purchase conversion tracking
• ✅ Enhanced Conversions via GTM using first-party customer data
• ✅ Scalable, privacy-compliant setup for osCommerce

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📁 Optional Add-ons

• 🔄 Server-side GTM setup for Enhanced Conversions
• 📉 GA4 to Google Ads audience syncing
• 🛒 Dynamic Remarketing using product data in osCommerce

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