Google Tag Manager Setup

Overview

Google Tag Manager (GTM) is a tag management system that manages marketing tags without modifying code directly. Campaign Cart SDK integrates with GTM by pushing analytics events to the standard data layer.

Setup

1. Add GTM Container

   Add the GTM container snippet to your page before the Campaign Cart SDK:

   <!-- Google Tag Manager -->
   <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
   new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
   j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
   'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
   })(window,document,'script','dataLayer','GTM-XXXXXX');</script>
   <!-- End Google Tag Manager -->

   Replace GTM-XXXXXX with your actual GTM container ID.

2. Enable GTM in SDK Config

   analytics: {
     providers: {
       gtm: {
         enabled: true,
         blockedEvents: ['dl_test_event']  // Optional
       }
     }
   }

3. Create GTM Triggers

   In Google Tag Manager:

   • Trigger Type: Custom Event
   • Event Name: dl_* (matches all events) or specific events like dl_add_to_cart

Where Events Are Pushed

Events are automatically pushed to two data layers:

1. window.dataLayer - Standard GTM data layer
2. window.ElevarDataLayer - Elevar-compatible format

This dual-layer approach provides compatibility with both standard GTM implementations and ecommerce tracking platforms.

Event Format

All events follow this standardized format in the data layer:

{
  event: 'dl_add_to_cart',
  ecommerce: {
    currency: 'USD',
    value: 99.99,
    items: [...]
  },
  user_properties: {
    visitor_type: 'guest',
    customer_email: '[email protected]'
  },
  // Attribution fields at root level for easy GTM access
  utm_source: 'google',
  utm_medium: 'cpc',
  funnel: 'main',
  affiliate: 'partner-123'
}

Common Events

The SDK pushes the following event types:

• dl_view_item - User views a product
• dl_add_to_cart - Item added to shopping cart
• dl_remove_from_cart - Item removed from cart
• dl_view_cart - User views the cart
• dl_begin_checkout - Checkout process initiated
• dl_add_shipping_info - Shipping information provided
• dl_add_payment_info - Payment information provided
• dl_purchase - Order completed

GTM Variables

Create these variables in GTM for easy access to event data:

Variable Name	Type	Value
DL - Event	Data Layer Variable	event
DL - Ecommerce	Data Layer Variable	ecommerce
DL - User Properties	Data Layer Variable	user_properties
DL - UTM Source	Data Layer Variable	utm_source
DL - UTM Medium	Data Layer Variable	utm_medium
DL - Funnel	Data Layer Variable	funnel
DL - Currency	Data Layer Variable	ecommerce.currency
DL - Value	Data Layer Variable	ecommerce.value
DL - Items	Data Layer Variable	ecommerce.items

Creating Variables in GTM

1. Open your GTM container
2. Navigate to Variables → User-Defined Variables
3. Click New for each variable
4. Select Data Layer Variable as the type
5. Enter the variable name and path
6. Save and publish your changes

GA4 Tag Setup

To send Campaign Cart analytics events to Google Analytics 4:

1. Create GA4 Event Tag
2. Event Name: {{DL - Event}}
3. Event Parameters:
   • currency: {{ecommerce.currency}}
   • value: {{ecommerce.value}}
   • items: {{ecommerce.items}}
4. Trigger: Custom Event dl_*

Complete GA4 Configuration Example

Tag Type: Google Analytics: GA4 Event
Measurement ID: G-XXXXXXXXXX
Event Name: {{DL - Event}}
Event Parameters:
  - currency: {{ecommerce.currency}}
  - value: {{ecommerce.value}}
  - items: {{ecommerce.items}}
  - user_id: {{user_properties.user_id}}
Trigger: Custom Event matching dl_*

Blocked Events

Block specific events from being sent to GTM to reduce noise and focus on important conversions:

gtm: {
  enabled: true,
  blockedEvents: [
    'dl_test_event',
    'internal_debug',
    'dev_event'
  ]
}

Why Block Events?

• Prevent low-priority events from cluttering your GTM logs
• Reduce GTM traffic (GTM charges based on page views)
• Focus on events that matter for your business
• Block test or debug events from production

Troubleshooting

Events Not Appearing in GTM

Problem: You’ve configured GTM but aren’t seeing events in the preview/debug mode.

Solutions:

1. Verify the GTM container snippet is loaded before the Campaign Cart SDK
2. Check that analytics.providers.gtm.enabled is set to true
3. Verify the GTM container ID is correct (GTM-XXXXXX)
4. Open GTM Preview mode and reload the page to see real-time events
5. Check browser console for any JavaScript errors

Events Not Triggering GA4 Tags

Problem: Events appear in GTM but aren’t reaching Google Analytics 4.

Solutions:

1. Verify your GA4 Event Tag is created and enabled
2. Check the trigger configuration - ensure it matches dl_* or the specific event name
3. Verify the Measurement ID in your GA4 tag is correct
4. Check GA4 real-time report to confirm events are arriving
5. Ensure Event Parameters are correctly mapped to data layer variables

Incorrect Event Data

Problem: Events are reaching GTM but with missing or incorrect data.

Solutions:

1. Verify data layer variables point to the correct data layer paths
2. Use GTM’s Preview mode to inspect the raw event payload
3. Check the ecommerce object structure matches GA4 requirements
4. Verify user_properties are being populated correctly
5. Ensure custom dimensions are correctly named and configured

Performance Issues

Problem: Site performance degrades after implementing GTM.

Solutions:

1. Load the GTM container asynchronously (it should load async by default)
2. Review the number of tags firing on each page
3. Consider delaying non-critical tag execution
4. Use GTM’s tag sequencing to optimize load order
5. Monitor tag firing frequency and optimize trigger conditions

Best Practices

1. Use Consistent Event Names

Keep event names consistent:

// Good
'dl_add_to_cart'
'dl_purchase'
'dl_begin_checkout'

// Avoid
'dl_event1'
'dl_tracking'
'dl_data'

2. Structure Data Consistently

The ecommerce object should follow the GA4 schema:

ecommerce: {
  currency: 'USD',
  value: 99.99,
  items: [
    {
      item_id: 'SKU123',
      item_name: 'Product Name',
      price: 99.99,
      quantity: 1
    }
  ]
}

3. Test Before Deploying

1. Use GTM’s Preview mode during development
2. Test each event type on staging
3. Verify data flows to GA4 before production
4. Monitor real-time reports after deploying

4. Document Your Implementation

Maintain documentation of:

• Which events you’re tracking
• What GTM variables you created
• Which tags use which triggers
• Any custom event modifications

5. Monitor and Iterate

• Regularly review GTM reports for data quality
• Check GA4 for anomalies or missing events
• Adjust blockedEvents list based on actual needs
• Update documentation as your implementation evolves

6. Use Version Control for GTM

• Export your GTM container configuration
• Store it in your project repository
• Document significant changes
• Maintain a changelog of GTM updates

7. Use Attribution Tracking

Use the root-level attribution fields:

{
  event: 'dl_purchase',
  utm_source: 'google',
  utm_medium: 'cpc',
  utm_campaign: 'summer_sale',
  funnel: 'main',
  affiliate: 'partner-123'
}

Create GTM variables for each attribution field to enable advanced segmentation and attribution analysis.

8. Handle Blocked Events Wisely

Only block events that:

• Are used for internal testing
• Generate excessive noise
• Aren’t needed for business analysis
• Can be filtered elsewhere

Document which events are blocked and why.

Migration Guide

If migrating from another analytics setup to GTM with Campaign Cart SDK:

1. Inventory existing events - Document all events you’re currently tracking
2. Map to Campaign Cart events - Match existing events to SDK event types
3. Set up GTM container - Follow the Setup section above
4. Test in parallel - Run both old and new tracking simultaneously
5. Validate data quality - Compare reports between old and new setup
6. Monitor initial period - Watch for discrepancies in first 2-4 weeks
7. Phase out old tracking - Gradually disable legacy tracking when confident

Additional Resources

• Google Tag Manager Documentation
• GA4 Event Schema
• Campaign Cart Analytics Documentation
• Event Reference