Analytics Tracking - Implementation & Auditing

Category: Marketing Tags: GA4, Google Tag Manager, event tracking, conversion tracking, UTM, analytics audit, consent mode

Overview

Analytics Tracking is the implementation layer for marketing measurement. Bad tracking is worse than no tracking -- duplicate events, missing parameters, unconsented data, and broken conversions lead to decisions based on bad data. This skill covers building tracking right the first time and finding what is broken when it is not.

This skill handles implementation only. For analyzing campaign performance data, use campaign-analytics. For product analytics and in-app behavior, use the product-team skills.

Operating Modes

Mode 1: Build From Scratch

No analytics in place. Build the tracking plan, implement GA4 + GTM, define event taxonomy, configure conversions.

Mode 2: Audit Existing Tracking

Tracking exists but data cannot be trusted. Audit coverage, identify gaps, clean up duplicates, fix consent issues.

Mode 3: Debug Specific Issues

Events are missing, conversions do not match, GTM preview shows fires but GA4 does not record. Structured debugging workflow.

Event Taxonomy Design

Get this right before touching GA4 or GTM. Retrofitting taxonomy is painful and expensive.

Naming Convention

Format: object_action (snake_case, past tense verb)

Correct	Wrong	Why Wrong
`form_submitted`	`submitForm`	camelCase, verb-first
`plan_selected`	`clickPricingPlan`	Implementation detail, not user action
`video_started`	`VideoStart`	PascalCase, inconsistent tense
`checkout_completed`	`purchase`	Ambiguous, not a verb phrase

Rules:

Always noun_verb order, never verb_noun
Snake_case only -- no camelCase, no hyphens, no PascalCase
Past tense verbs: _started, _completed, _failed, _viewed
Specific enough to be unambiguous, not so verbose it is a sentence
Prefix with domain when needed: onboarding_step_completed, billing_plan_selected

Standard Event Parameters

Every custom event should include applicable parameters from this table:

Parameter	Type	Example	Required When
`user_id`	string	`usr_abc123`	Always (if authenticated)
`plan_name`	string	`professional`	Billing/pricing events
`value`	number	`99.00`	Revenue events
`currency`	string	`USD`	Always with value
`content_group`	string	`onboarding`	Page/flow grouping
`method`	string	`google_oauth`	Signup/login events
`step_name`	string	`connect_account`	Multi-step flows
`step_number`	number	`3`	Multi-step flows
`source`	string	`pricing_page`	CTA click events

SaaS Event Taxonomy (Reference)

Core Funnel:

visitor_arrived              (automatic page_view in GA4)
signup_started               (user clicked "Sign up")
signup_completed             (account created)
trial_started                (free trial began)
onboarding_step_completed    (params: step_name, step_number)
feature_activated            (params: feature_name)
plan_selected                (params: plan_name, billing_period)
checkout_started             (params: value, currency, plan_name)
checkout_completed           (params: value, currency, transaction_id)
subscription_renewed         (params: value, plan_name)
subscription_cancelled       (params: cancel_reason, plan_name)

Micro-Conversions:

pricing_viewed
demo_requested               (params: source)
form_submitted               (params: form_name, form_location)
content_downloaded           (params: content_name, content_type)
video_started                (params: video_title)
video_completed              (params: video_title, percent_watched)
chat_opened
help_article_viewed          (params: article_name)
invite_sent                  (params: recipient_role)
integration_connected        (params: integration_name)

GA4 Configuration

Data Stream Setup

Create property: GA4 Admin > Properties > Create
Add web data stream with your domain
Enhanced Measurement -- review each:
- Page views: Keep enabled
- Scrolls: Keep enabled
- Outbound clicks: Keep enabled
- Site search: Enable if you have search
- Video engagement: Disable if tracking videos manually (avoids duplicates)
- File downloads: Disable if tracking via GTM (for better parameters)
Configure domains: add all subdomains in your funnel
Data retention: Set to 14 months (maximum for free GA4)

Conversion Events

Mark as conversions in GA4 Admin > Conversions:

signup_completed
checkout_completed
demo_requested
trial_started

Rules:

Maximum 30 conversion events per property -- curate carefully
GA4 conversions are retroactive for 6 months when enabled
Do not mark micro-conversions as conversions unless optimizing ad campaigns for them
Conversion counting: set to "once per session" for lead events, "every" for purchase events

Custom Dimensions

Parameter	Scope	Dimension Name
`plan_name`	Event	Plan Name
`user_id`	User	User ID
`content_group`	Event	Content Group
`feature_name`	Event	Feature Name

Google Tag Manager Implementation

Container Architecture

GTM Container
├── Tags
│   ├── GA4 Configuration (All Pages trigger)
│   ├── GA4 Event Tags (one per custom event)
│   ├── Google Ads Conversion Tags (per conversion action)
│   └── Meta Pixel / LinkedIn Insight (if running ads)
├── Triggers
│   ├── All Pages (Page View)
│   ├── DOM Ready
│   ├── Custom Event triggers (one per dataLayer event)
│   └── Element Click triggers (CSS selector based)
└── Variables
    ├── Data Layer Variables (one per dataLayer key)
    ├── Constants (GA4 Measurement ID, etc.)
    └── Lookup Tables (if needed for mapping)

Implementation Pattern: Data Layer Push

Your application pushes events to the data layer. GTM picks them up and sends to GA4.

Application code:

// Push event when user completes signup
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  event: 'signup_completed',
  method: 'email',
  user_id: userId,
  plan_name: 'trial'
});

GTM configuration:

Trigger:
  Type: Custom Event
  Event name: signup_completed

Tag:
  Type: GA4 Event
  Event name: signup_completed
  Parameters:
    method:    {{DLV - method}}
    user_id:   {{DLV - user_id}}
    plan_name: {{DLV - plan_name}}

SPA Handling

Single Page Applications need special attention because page views do not fire automatically on route changes.

Option A: History change trigger (GTM built-in)

Enable "History Change" trigger in GTM
Fires GA4 page_view on every pushState/popState

Option B: DataLayer push on route change (more control)

// In your router (React Router, Next.js, etc.)
router.events.on('routeChangeComplete', (url) => {
  window.dataLayer.push({
    event: 'page_view',
    page_location: url,
    page_title: document.title
  });
});

Conversion Tracking: Ad Platforms

Google Ads

Recommended approach: Import GA4 conversions into Google Ads (single source of truth).

Link GA4 and Google Ads accounts
In Google Ads > Goals > Conversions > Import > Google Analytics
Select GA4 conversion events to import
Set attribution model: Data-driven (if 50+ conversions/month), otherwise Last-click
Conversion window: 30 days for lead gen, 90 days for high-consideration B2B

Enhanced Conversions: Enable for 15-30% better conversion measurement. Sends hashed first-party data (email, phone) to match conversions that cookies miss.

Meta (Facebook/Instagram)

Install Meta Pixel base code via GTM
Configure standard events: PageView, Lead, CompleteRegistration, Purchase
Conversions API (CAPI): strongly recommended -- client-side pixel loses approximately 30% of conversions due to ad blockers and iOS App Tracking Transparency
Deduplication: when using both pixel and CAPI, send the same event_id to prevent double-counting

LinkedIn Insight Tag

Install via GTM (Tag type: LinkedIn Insight)
Configure conversion events in LinkedIn Campaign Manager
Match events to your taxonomy: signup_completed -> LinkedIn "Sign-up" conversion

UTM Strategy

Convention Enforcement

Parameter	Convention	Example
`utm_source`	Platform name, lowercase	`google`, `linkedin`, `newsletter`
`utm_medium`	Traffic type	`cpc`, `email`, `social`, `organic`
`utm_campaign`	Campaign identifier	`q1-trial-push`, `brand-awareness-2026`
`utm_content`	Creative variant	`hero-cta-blue`, `sidebar-text-link`
`utm_term`	Paid keyword (search only)	`saas-analytics-tool`

Critical rules:

Never tag organic traffic with UTMs (overrides GA4 automatic attribution)
Never tag direct/internal links with UTMs
Use a UTM builder spreadsheet or tool -- manual entry causes inconsistency
Lowercase everything -- Google and google are different sources in GA4

Attribution Windows

Platform	Default	Recommended for SaaS
GA4	30 days	30-90 days (match your sales cycle)
Google Ads	30 days	30 days (trial), 90 days (enterprise)
Meta	7-day click, 1-day view	7-day click only (view-through inflates)
LinkedIn	30 days	30 days

Cross-Domain Tracking

For funnels crossing domains (e.g., acme.com to app.acme.com):

GA4 Admin > Data Streams > Configure tag settings > Configure your domains > Add both domains
GTM: GA4 Configuration tag > Fields to Set > linker > Add domains
Admin > Data Streams > List unwanted referrals > Add both domains

Verification: Visit domain A, click link to domain B, check GA4 DebugView. The session should NOT restart. If a new session starts, cross-domain tracking is broken.

Consent Management

Consent Mode v2

Required for EU compliance and for maintaining data quality in consent-heavy markets.

Setting	No Consent Mode	Basic	Advanced
User declines cookies	Zero data	Zero data	Modeled data (GA4 estimates)
Data quality impact	25-40% data loss in EU	25-40% data loss	5-15% data loss
Implementation effort	None	Medium	Medium-High

Recommendation: Implement Advanced Consent Mode v2 via GTM with a CMP (Cookiebot, OneTrust, Usercentrics).

Expected consent rates by region:

EU/EEA: 60-75%
UK: 70-80%
US: 85-95%
Rest of world: 80-90%

Implementation via GTM

1. Install CMP tag (fires first, before any other tags)
2. Set default consent state:
   - analytics_storage: denied
   - ad_storage: denied
   - ad_user_data: denied
   - ad_personalization: denied
3. CMP updates consent state on user choice
4. GA4 and ad tags respect consent automatically

Data Quality Auditing

Audit Checklist

Event Quality:

No duplicate events (check GTM Preview for double-fires)
All custom events have required parameters
Event names follow naming convention
No PII in event parameters (names, emails, phone numbers)
Enhanced Measurement not duplicating GTM custom events

Configuration Quality:

Data retention set to 14 months
Internal traffic filter enabled (office and developer IPs)
Bot filtering enabled (default in GA4)
Cross-domain tracking working (if applicable)
Custom dimensions registered for filtered parameters
Conversion events marked correctly

Consent Quality:

Consent Mode v2 implemented (if serving EU users)
CMP banner appearing on first visit
Tags respect consent state (no firing before consent)
Consent state persisting across pages

Common Data Quality Issues

Issue	Symptom	Root Cause	Fix
Inflated page views	2x expected volume	GTM page_view + Enhanced Measurement	Disable Enhanced page_view
Missing conversions	GA4 and Ads numbers differ	Attribution window mismatch	Align windows
(not set) pages	Pages show as "/(not set)"	SPA routing not handled	Implement SPA tracking
Self-referrals	Own domain in referral report	Missing cross-domain config	Add domains to referral exclusion
Direct traffic spike	Paid traffic showing as direct	UTMs missing or stripped	Audit UTM usage
Zero EU data	No traffic from EU markets	Consent blocks all tracking	Implement Advanced Consent Mode

Debugging Workflow

Step 1: Open GTM Preview mode
  - Is the tag firing? Check triggers and conditions
  - Is the data layer populated? Check dataLayer in console

Step 2: Check GA4 DebugView (Admin > DebugView)
  - Is the event appearing? If yes, GTM is working
  - Are parameters populated? Check parameter values

Step 3: Check GA4 Realtime report
  - Events appearing with 5-minute delay? Normal
  - Events not appearing at all? Check measurement ID

Step 4: Check Network tab (DevTools)
  - Filter by "collect" or "analytics"
  - Is the request being sent? Check status code
  - Is the request being blocked? Check ad blockers / consent

Proactive Triggers

Surface these findings without being asked:

Events firing on every page load with identical parameters: misconfigured trigger causing data inflation
No user_id parameter on authenticated events: cannot connect analytics to CRM or understand cohorts
GA4 conversion count differs from Google Ads by more than 15%: attribution window or deduplication issue
No consent mode in EU markets: legal exposure and 25-40% data underreporting
All pages showing as /(not set): SPA routing not handled properly
utm_source showing as direct for known paid campaigns: UTMs missing or being stripped by redirects

Related Skills

Skill	Use When
campaign-analytics	Analyzing marketing performance and channel ROI (not implementation)
ab-test-setup	Designing experiments (this skill's events feed A/B tests)
launch-strategy	Tracking events for product launches
email-sequence	Setting up email click tracking and UTM parameters

analytics-tracking