AdRoll Cross-Domain Tracking | Blue Frog Docs

AdRoll Cross-Domain Tracking

Configure multi-domain and subdomain tracking for unified AdRoll audiences across separate websites, stores, and content properties.

Cross-Domain Tracking Overview

Cross-domain tracking allows AdRoll to maintain user identity across multiple domains (e.g., marketing-site.com and shop.brand.com) or subdomains (e.g., www.example.com and blog.example.com). Without cross-domain tracking, AdRoll treats each domain as separate users, fragmenting audiences and losing attribution when users navigate between sites.

Use Cases

  • Separate marketing and e-commerce sites: brand.com → shop.brand.com
  • Blog on subdomain: example.com → blog.example.com
  • Multi-brand portfolios: brand-a.com + brand-b.com under single advertiser
  • Third-party checkout: yoursite.com → checkout.payment-provider.com
  • Localized domains: example.com (US) + example.co.uk (UK) + example.de (Germany)

How Cross-Domain Tracking Works

  1. Same pixel across domains: Install identical AdRoll pixel (same advertiser + pixel IDs) on all domains
  2. Cookie sharing: AdRoll passes user ID via URL parameters when navigating between domains
  3. Domain approval: Add all domains to approved list in AdRoll dashboard
  4. Unified audiences: Users tracked across domains appear as single user in audiences

Prerequisites

  • AdRoll pixel installed on primary domain
  • Access to edit all domains you want to track
  • Domain verification completed for all domains
  • Same advertiser ID and pixel ID used across all domains

Setup Steps

1. Add Domains to Approved List

AdRoll Dashboard:

  1. Navigate to Settings → Pixels → Approved Domains
  2. Click Add Domain
  3. Enter each domain and subdomain:
    • example.com
    • www.example.com
    • shop.example.com
    • blog.example.com
  4. Click Save

Important:

  • Add ALL variations (with and without www)
  • Include both HTTP and HTTPS if site supports both (though HTTPS is recommended)
  • Subdomains must be added separately (e.g., blog.example.com is separate from example.com)

2. Install Pixel on All Domains

Use the exact same pixel code (identical advertiser ID and pixel ID) on every domain:

<!-- SAME pixel code on all domains -->
<script type="text/javascript">
  adroll_adv_id = "ABC123XYZ"; // SAME ID everywhere
  adroll_pix_id = "DEF456GHI"; // SAME ID everywhere
  adroll_version = "2.0";

  (function(w, d, e, o, a) {
    w.__adroll_loaded = true;
    w.adroll = w.adroll || [];
    w.adroll.f = [ 'setProperties', 'identify', 'track' ];
    var roundtripUrl = "https://s.adroll.com/j/" + adroll_adv_id + "/roundtrip.js";
    for (a = 0; a < w.adroll.f.length; a++) {
      w.adroll[w.adroll.f[a]] = w.adroll[w.adroll.f[a]] || (function(n) {
        return function() {
          w.adroll.push([ n, arguments ])
        }
      })(w.adroll.f[a])
    }
    e = d.createElement('script');
    o = d.getElementsByTagName('script')[0];
    e.async = 1;
    e.src = roundtripUrl;
    o.parentNode.insertBefore(e, o);
  })(window, document);
</script>

Deploy to:

  • Main site: example.com
  • E-commerce: shop.example.com
  • Blog: blog.example.com
  • Any other properties

3. Verify Cross-Domain Parameter Passing

AdRoll automatically appends tracking parameters when users navigate between domains:

Example navigation:

User on: example.com
Clicks link to: shop.example.com

Link becomes: shop.example.com?adroll_fpc=abc123...
              ↑ AdRoll user ID parameter

No code changes needed - AdRoll handles parameter passing automatically when:

  • Pixel is installed on both domains
  • Both domains are in approved list
  • User clicks a link (not typing URL directly)

Subdomain Tracking

Automatic Subdomain Tracking

For subdomains under the same root domain (e.g., www.example.com and blog.example.com), AdRoll shares cookies automatically:

Setup:

  1. Install pixel on all subdomains
  2. Add each subdomain to approved domains list
  3. No additional configuration needed

Example:

Domains to track:
- www.example.com (main site)
- blog.example.com (blog)
- shop.example.com (store)

AdRoll approved domains:
✓ www.example.com
✓ blog.example.com
✓ shop.example.com

Cookie behavior:

  • AdRoll sets cookies on .example.com (root domain)
  • Cookies accessible from all subdomains automatically
  • User ID persists across subdomain navigation

Multi-Domain Tracking (Different Root Domains)

Setup for Separate Domains

For completely different domains (e.g., brand-a.com and brand-b.com):

1. Install same pixel on both:

<!-- brand-a.com -->
<script>
  adroll_adv_id = "ABC123XYZ"; // Same ID
  adroll_pix_id = "DEF456GHI"; // Same ID
  /* ... */
</script>

<!-- brand-b.com -->
<script>
  adroll_adv_id = "ABC123XYZ"; // Same ID
  adroll_pix_id = "DEF456GHI"; // Same ID
  /* ... */
</script>

2. Add both domains to approved list:

  • brand-a.com
  • www.brand-a.com
  • brand-b.com
  • www.brand-b.com

3. Link between domains:

When linking from one domain to another, ensure links allow AdRoll to pass user ID:

<!-- brand-a.com linking to brand-b.com -->
<a href="https://brand-b.com/products">Visit Brand B</a>
<!-- AdRoll automatically appends: ?adroll_fpc=... -->

No JavaScript needed - AdRoll intercepts link clicks and adds parameters automatically.

If automatic parameter passing doesn't work (e.g., JavaScript navigation), manually decorate links:

// Get AdRoll user ID
function getAdRollUserId() {
  const cookies = document.cookie.split(';');
  for (let cookie of cookies) {
    const [name, value] = cookie.trim().split('=');
    if (name === '__adroll_fpc') {
      return value;
    }
  }
  return null;
}

// Add AdRoll parameter to cross-domain links
function decorateCrossDomainLinks() {
  const userId = getAdRollUserId();
  if (!userId) return;

  const crossDomainLinks = document.querySelectorAll('a[href*="shop.brand.com"]');
  crossDomainLinks.forEach(link => {
    const url = new URL(link.href);
    url.searchParams.set('adroll_fpc', userId);
    link.href = url.toString();
  });
}

// Run on page load
decorateCrossDomainLinks();

JavaScript Navigation

For SPA or programmatic navigation:

// React example: navigate to different domain
function navigateToStore(productId) {
  const userId = getAdRollUserId();
  const url = `https://shop.brand.com/products/${productId}?adroll_fpc=${userId}`;

  window.location.href = url;
}

// Or for window.open()
function openInNewTab(url) {
  const userId = getAdRollUserId();
  const decoratedUrl = `${url}?adroll_fpc=${userId}`;

  window.open(decoratedUrl, '_blank');
}

Third-Party Checkout Integration

Payment Processor Checkout (e.g., Stripe, PayPal)

When redirecting to third-party checkout, maintain tracking:

Problem: User goes from yoursite.com → checkout.stripe.com → back to yoursite.com/confirmation

  • AdRoll can't track on checkout.stripe.com (third-party domain)
  • User ID may be lost during roundtrip

Solution: Pass user ID via return URL

1. Before redirecting to checkout:

// Capture AdRoll user ID
const adrollUserId = getAdRollUserId();

// Store in session or pass via checkout URL
sessionStorage.setItem('adroll_user_id', adrollUserId);

// Or append to return URL
const returnUrl = `https://yoursite.com/confirmation?order_id=123&adroll_fpc=${adrollUserId}`;

// Redirect to Stripe with custom return URL
redirectToStripe({
  success_url: returnUrl,
  cancel_url: 'https://yoursite.com/cart'
});

2. On return to confirmation page:

// confirmation.html
// Check URL for adroll_fpc parameter
const params = new URLSearchParams(window.location.search);
const adrollUserId = params.get('adroll_fpc') || sessionStorage.getItem('adroll_user_id');

// Re-establish AdRoll tracking
if (adrollUserId) {
  document.cookie = `__adroll_fpc=${adrollUserId}; path=/; domain=.yoursite.com`;
}

// Fire conversion event
adroll.track("purchase", {
  order_id: params.get('order_id'),
  conversion_value: 99.99,
  currency: "USD"
});

Multi-Brand / Multi-Advertiser Setup

Option 1: Single Advertiser (Shared Audiences)

Use when brands share audiences for cross-selling:

Setup:

  • One advertiser ID for all brands
  • Same pixel on brand-a.com, brand-b.com, brand-c.com
  • All brands share audiences (user who visits Brand A can see Brand B ads)

Example:

// brand-a.com
adroll_adv_id = "ABC123XYZ";
adroll_pix_id = "DEF456GHI";

// brand-b.com (SAME IDs)
adroll_adv_id = "ABC123XYZ";
adroll_pix_id = "DEF456GHI";

// brand-c.com (SAME IDs)
adroll_adv_id = "ABC123XYZ";
adroll_pix_id = "DEF456GHI";

Audience segmentation:

// Tag each brand's visitors differently
// brand-a.com
adroll.track("pageView", {
  segment_name: "brand_a_visitors",
  brand: "Brand A"
});

// brand-b.com
adroll.track("pageView", {
  segment_name: "brand_b_visitors",
  brand: "Brand B"
});

// Create campaigns:
// - Campaign 1: Show Brand B ads to "brand_a_visitors"
// - Campaign 2: Show Brand A ads to "brand_b_visitors"

Option 2: Separate Advertisers (Isolated Audiences)

Use when brands should NOT share audiences:

Setup:

  • Different advertiser IDs for each brand
  • Different pixels on each domain
  • Audiences completely separate

Example:

// brand-a.com
adroll_adv_id = "ABC123AAA"; // Brand A advertiser
adroll_pix_id = "DEF456AAA";

// brand-b.com
adroll_adv_id = "ABC123BBB"; // Brand B advertiser (different)
adroll_pix_id = "DEF456BBB";

When to use:

  • Brands target different customer segments
  • Different marketing teams/budgets
  • Privacy requirements prevent data sharing

Localized Domain Tracking

Multi-Country Domains

For international sites (e.g., example.com, example.co.uk, example.de):

Option 1: Unified global audience

// Same pixel on all country sites
// example.com, example.co.uk, example.de
adroll_adv_id = "ABC123XYZ"; // Same everywhere
adroll_pix_id = "DEF456GHI";

// Segment by country
adroll.track("pageView", {
  segment_name: "visitors_uk",
  country: "UK",
  currency: "GBP"
});

Option 2: Region-specific advertisers

// example.com (US)
adroll_adv_id = "ABC123USA";

// example.co.uk (UK)
adroll_adv_id = "ABC123GBR";

// example.de (Germany)
adroll_adv_id = "ABC123DEU";

Benefits of unified:

  • See global customer journey
  • Retarget US visitors with UK site (if they travel)
  • Consolidated reporting

Benefits of separate:

  • Region-specific budgets and targeting
  • Comply with local privacy laws (GDPR)
  • Currency and language isolation

Testing Cross-Domain Tracking

Manual Testing

1. Test navigation between domains:

a. Visit example.com with AdRoll pixel installed b. Open browser DevTools → Application → Cookies c. Find __adroll_fpc cookie, copy value (e.g., abc123xyz456) d. Click link to shop.example.com e. Check cookies on shop.example.com f. Verify __adroll_fpc value matches original (or URL has ?adroll_fpc=abc123xyz456)

2. Check URL parameters:

Navigate from domain A to domain B
Check URL of domain B:

✓ GOOD: shop.example.com/products?adroll_fpc=abc123xyz456
✗ BAD:  shop.example.com/products (no parameter)

3. Test audience membership:

a. Visit both domains from same browser b. Wait 24-48 hours c. Check AdRoll → Audiences → All Visitors d. Audience size should reflect unique users, not pageviews across domains

Automated Testing

// test-cross-domain.js
// Run in browser console on first domain

(async function testCrossDomain() {
  console.log('=== AdRoll Cross-Domain Test ===');

  // 1. Check pixel loaded
  if (typeof adroll === 'undefined') {
    console.error('❌ AdRoll pixel not loaded');
    return;
  }
  console.log('✓ AdRoll pixel loaded');

  // 2. Check advertiser/pixel IDs
  console.log('Advertiser ID:', adroll_adv_id);
  console.log('Pixel ID:', adroll_pix_id);

  // 3. Check cookie
  const cookies = document.cookie.split(';');
  let fpCookie = null;
  for (let cookie of cookies) {
    const [name, value] = cookie.trim().split('=');
    if (name === '__adroll_fpc') {
      fpCookie = value;
      console.log('✓ AdRoll user ID cookie:', fpCookie);
    }
  }
  if (!fpCookie) {
    console.error('❌ AdRoll cookie not found');
    return;
  }

  // 4. Test cross-domain link decoration
  const crossDomainLinks = document.querySelectorAll('a[href*="shop.example.com"]');
  console.log(`Found ${crossDomainLinks.length} cross-domain links`);

  // Simulate click to see if parameter added
  if (crossDomainLinks.length > 0) {
    const testLink = crossDomainLinks[0];
    console.log('Test link BEFORE:', testLink.href);

    // Trigger AdRoll's link decoration
    testLink.click(); // Or just inspect the href after AdRoll processes it
  }

  console.log('=== Test Complete ===');
})();

Troubleshooting

Cookies Not Persisting Across Domains

Symptoms:

  • User ID different on each domain
  • Audiences count same user multiple times

Causes & Fixes:

1. Different advertiser/pixel IDs:

// WRONG - Different IDs on each domain
// domain-a.com
adroll_adv_id = "ABC123";

// domain-b.com
adroll_adv_id = "XYZ789"; // DIFFERENT!

// FIX: Use same IDs on all domains

2. Domains not in approved list:

  • Check Settings → Pixels → Approved Domains
  • Add missing domains

3. Browser blocking third-party cookies:

  • Safari ITP and Firefox Enhanced Tracking Protection limit cookie lifespan
  • Consider first-party subdomain CNAME (contact AdRoll support)

4. Link navigation method:

// WRONG - Direct navigation loses parameter
window.location.replace('https://shop.brand.com');

// CORRECT - Use regular link click (AdRoll auto-decorates)
<a href="https://shop.brand.com">Shop</a>

// OR manually add parameter
window.location.href = 'https://shop.brand.com?adroll_fpc=' + getAdRollUserId();

Conversion Attribution Lost After Domain Hop

Symptoms:

  • User clicks ad on brand.com, converts on shop.brand.com
  • Conversion not attributed to campaign

Fix:

  1. Ensure same pixel on both domains
  2. Verify approved domains includes both
  3. Check conversion event fires on shop.brand.com confirmation page
  4. Review attribution window (may need to extend from 30 to 60 days)

Audience Size Inflated

Symptoms:

  • Audience size much larger than actual unique users
  • Each domain visit counts as new user

Diagnosis:

// Check if user IDs are consistent across domains

// On domain-a.com
console.log('Domain A user ID:', document.cookie.match(/__adroll_fpc=([^;]+)/)?.[1]);

// On domain-b.com (after navigating from domain-a)
console.log('Domain B user ID:', document.cookie.match(/__adroll_fpc=([^;]+)/)?.[1]);

// IDs should MATCH
// If different, cross-domain tracking is broken

Fix:

  • Verify URL parameter ?adroll_fpc= appears when navigating between domains
  • Check both domains have pixel installed
  • Ensure link clicks (not typed URLs) for automatic parameter passing

Best Practices

For subdomains, AdRoll automatically sets cookies on root domain:

Site structure:
- www.example.com
- shop.example.com
- blog.example.com

AdRoll cookie domain: .example.com (note leading dot)
→ Accessible from all subdomains automatically

No configuration needed - AdRoll handles this automatically.

Privacy & Consent Management

When tracking across domains in EU:

// Only initialize AdRoll after consent
if (userConsentedToTracking) {
  // Load AdRoll pixel
  const script = document.createElement('script');
  script.innerHTML = `
    adroll_adv_id = "ABC123XYZ";
    adroll_pix_id = "DEF456GHI";
    // ... rest of pixel code
  `;
  document.head.appendChild(script);
}

// Track consent across domains
localStorage.setItem('adroll_consent', userConsentedToTracking);

// On other domain, check consent before loading pixel
if (localStorage.getItem('adroll_consent') === 'true') {
  // Load pixel
}

Documentation

Document your cross-domain setup:

# AdRoll Cross-Domain Tracking

**Advertiser ID:** ABC123XYZ
**Pixel ID:** DEF456GHI

**Tracked Domains:**
- example.com (main site)
- www.example.com (www variant)
- shop.example.com (e-commerce)
- blog.example.com (content)

**Audience Strategy:**
- All domains share audiences
- Segment by domain via `segment_name` parameter
- Cross-sell: Retarget blog readers with shop products

**Updated:** 2025-01-15

Next Steps

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