GA4 Audit Essentials - The Critical 15 Items Every Marketer Must Fix

1. Go to Admin → Data Settings → Data Retention
2. Change from "2 months" to "14 months"
3. Click Save

1. Admin → Events
2. Find your conversion event (purchase, generate_lead, sign_up)
3. Toggle "Mark as key event" to ON
4. Repeat for all conversion events

1. Admin → Data Streams → [Your Stream] → Configure tag settings
2. Show more → Define internal traffic
3. Click "Create" and add your IP addresses:
   - traffic_type: internal
   - IP address: matches regex: YOUR_IP_HERE
4. Go to Admin → Data Settings → Data Filters
5. Find "Internal Traffic" filter
6. Change from "Testing" to "Active"

1. Admin → Product Links → Google Ads Links → Link
2. Choose your Google Ads account
3. Enable "Personalized advertising" if you want audiences
4. After linking, go to Google Ads:
   - Tools → Conversions → Import
   - Select GA4 property
   - Import your key events as conversions

Google Ads:
1. Settings → Account Settings
2. Auto-tagging: Turn ON
3. Check "Tag the URL that people click through from my ad"

gtag('config', 'G-XXXXXXXXXX', {
  'allow_google_signals': true,  'allow_ad_personalization_signals': true});

// BAD: Same transaction ID'transaction_id': 'ORDER_12345'// GOOD: Unique transaction ID'transaction_id': 'ORDER_' + Date.now() + '_' + Math.random()
// BETTER: Use your actual order ID from database'transaction_id': orderData.id  // e.g., "ORD_2025_12345"

1. Reports → Monetization → Ecommerce purchases
2. Look at transaction_id column
3. If you see duplicates, you have a problem

Step 1: Export GA4 Revenue
- Reports → Monetization → Ecommerce purchases
- Date range: Last month
- Total revenue = $______

Step 2: Check Payment Processor
- Stripe/PayPal dashboard
- Same date range
- Total revenue = $______

Step 3: Compare
- If within 2-5% difference: OK (expected variance)
- If >5% difference: You have a tracking problem

Source (utm_source):
✅ facebook, google, linkedin, twitter
❌ Facebook, FACEBOOK, fb

Medium (utm_medium):
✅ cpc, email, social, organic
❌ paid, paid-search, PPC

Campaign (utm_campaign):
✅ q4_promo_2025
❌ Q4 Promo 2025!

Rules:
- Always lowercase
- Use underscores, not spaces
- No special characters
- Be consistent

1. Admin → Data Streams → [Your Stream] → Enhanced measurement
2. Click the gear icon ⚙️
3. Review each option:

Page views: ✅ Keep ON
Scrolls: ✅ Keep ON (90% depth)
Outbound clicks: ✅ Keep ON
Site search: ⚠️ Configure search query parameter
Video engagement: ⚠️ ON only if you embed videos
File downloads: ⚠️ Review file extensions

// BAD: Sending emailgtag('event', 'form_submit', {
  'user_email': '[email protected]'  // ❌ NEVER DO THIS});// GOOD: Hash or use IDgtag('event', 'form_submit', {
  'user_id': 'user_abc123',  // ✅ Hashed or anonymized ID  'form_type': 'contact'});

Formula:
Lead Value = (Annual Revenue ÷ Total Customers) × Conversion Rate

Example:
- Annual Revenue: $500,000
- Total Customers: 200
- Conversion Rate: 5%
- Lead Value = ($500,000 ÷ 200) × 0.05 = $125 per lead

gtag('event', 'generate_lead', {
  'currency': 'USD',  'value': 125,  // ✅ Estimated lead value  'lead_type': 'demo_request'});gtag('event', 'sign_up', {
  'currency': 'USD',  'value': 50,  // ✅ Trial signup value  'signup_type': 'free_trial'});

// On form submissiondocument.getElementById('contactForm').addEventListener('submit', function(e) {
  gtag('event', 'generate_lead', {
    'currency': 'USD',    'value': 100,  // Your lead value    'form_id': 'contact_form',    'form_type': 'contact',    'form_location': 'homepage'  });});

1. Explore → Create new exploration
2. Choose "Funnel exploration"
3. Add steps:
   - Step 1: view_item (Product page)
   - Step 2: add_to_cart (Add to cart)
   - Step 3: begin_checkout (Start checkout)
   - Step 4: purchase (Complete purchase)
4. Save and review weekly

// Test ordersif (isTestOrder) {
  gtag('event', 'purchase', {
    'transaction_id': 'TEST_' + Date.now(),  // Starts with TEST_    // ... rest of data  });}

Admin → Data Settings → Data Filters → Create filter
Parameter: transaction_id
Match type: begins_with
Value: TEST_
Action: Exclude

1. Admin → Property Settings
2. Currency: Select your currency (USD, EUR, INR, etc.)
3. ⚠️ NOTE: You can change this, but historical data won't be recalculated

gtag('event', 'purchase', {
  'currency': 'USD',  // ✅ Always specify  'value': 99.99});