Cross-Platform Attribution Health Audit

Attribution decay is the silent revenue killer of 2026 — Consent Mode V2 EEA enforcement (Jul 21, 2025), iOS ATT, SKAdNetwork → AdAttributionKit migration, and the death of third-party cookies have moved every advertiser's attribution signal toward modeled, server-side, first-party data. Misaligned attribution windows or unverified Consent Mode setups will mis-attribute 15-40% of conversions and silently waste budget.

Process

1. Collect current attribution stack: GA4 property ID, Google Ads conversion

actions, Meta CAPI config, Apple Ads / AdAttributionKit registration, MMP dashboard (AppsFlyer / Adjust / Branch / Singular), any sGTM container

1. Read ads/references/conversion-tracking.md for the cross-platform

tracking baseline

1. Evaluate attribution health per surface (web, iOS app, Android app,

server-side)

1. Score each surface PASS / WARNING / FAIL
2. Generate findings report with cross-channel attribution map and remediation

plan

What to Analyze

iOS Attribution (AdAttributionKit + ATT)

• AdAttributionKit registered with Apple Ads (post-Apr 10, 2025 cutover);

registration creates dual attribution with SKAdNetwork (SKAN v1-3)

• View-through attribution active — 24h post-impression view window

configured on Apple Ads campaigns where applicable

• Configurable attribution windows (WWDC 2025): per-campaign window

customization audited; overlapping re-engagement windows used for subscription / re-acquisition campaigns

• Country code in postbacks (WWDC 2025): enabled if you need geo

attribution detail

• ATT (App Tracking Transparency) opt-in rate monitored; <30% opt-in

means heavy reliance on SKAN/AAK + privacy threshold

• Privacy threshold awareness — low-volume campaigns may receive null

postbacks; campaign consolidation recommended below 1k installs/week

Web Attribution (GA4 + Google Ads + Meta CAPI)

• GA4 attribution model: Data-Driven (default for properties with enough

data) vs Last-Click — confirm setting is intentional, not residue from a pre-2026 migration

• Google Ads attribution model: Data-Driven default; per-conversion

override allowed but audit any Last-Click overrides for justification

• Cross-channel attribution in GA4: confirm Google Ads, Meta, LinkedIn,

TikTok, Microsoft are integrated as platforms with consent + auto-tagging

• Conversion windows per channel appropriate to sales cycle:
• E-commerce: 7-day click, 1-day view
• B2B / lead gen: 30-90 day click, no view
• SaaS subscription: 30 day click, 1-day view, plus offline conversion

import for the activation event

• Conversion lag analysis run quarterly to validate window choice

Consent Mode V2 (EU/EEA + recommended globally)

• Consent Mode V2 active (enforcement began Jul 21, 2025 for EEA/UK)
• Advanced Mode (not Basic) — Basic loses ~25% of EEA conversion signal
• 700+ ad clicks/day over 7 days per country/domain threshold met for

Advanced Mode behavioral modeling to activate

• Signal recovery measured: aim 15-25% conversion recovery vs pre-CMV2

baseline

• Consent banner correctly reads CMV2 signals (not just GDPR boilerplate)

Server-Side Attribution Stitching

• First-party server logs stored with user_id + event_id + timestamp

+ platform tag for every conversion event

• MMP + first-party stitching: MMP (AppsFlyer / Adjust / Branch /

Singular) receives both client-side AND server-side events with shared event_id for deduplication

• Server-side conversion import to Google Ads (offline conversion import)

and Meta (CAPI) within 72h of the conversion event

• Hash quality: email / phone fields SHA-256 hashed and lowercased

before send; cross-platform hashing convention consistent

• Deduplication rate ≥90% (matched event_id between client + server)

MMP Health (Mobile Apps)

• MMP integrated — AppsFlyer / Adjust / Branch / Singular set up before

any paid campaigns launched

• Apple Ads connected as a partner in MMP dashboard
• Post-install events sent back to Apple Ads, Google UAC, Meta App

Campaigns, TikTok (enables Maximize Conversions and ROAS bidding)

• Event quality: purchase, subscription_start, trial_start, or other

revenue events tracked (not just install → registration)

• Postback configuration: SKAN/AAK conversion values map to meaningful

user actions

Cross-Device & Cross-Platform Attribution

• Customer Match lists synced to Google Ads, Meta (Customer File CA),

LinkedIn Matched Audiences, TikTok Customer File for cross-device stitching

• Enhanced Conversions active for Google Ads (hashed first-party data,

~10% uplift on properly-implemented setups)

• CAPI customer_information parameters (em, ph, fn, ln, ct,

st, zp, external_id) sent server-side to Meta

• Privacy-safe identifiers (Customer Match hashes, GAID/IDFA where

permitted) included in conversion exports

Key Thresholds

Output

Attribution Health Score

Attribution Health Score: XX/100 (Grade: X)

iOS (AdAttributionKit + ATT):    XX/100  ████████░░  (20%)
Web (GA4 + Ads + CAPI):           XX/100  ██████████  (30%)
Consent Mode V2:                  XX/100  █████████░  (15%)
Server-Side Stitching:            XX/100  ████████░░  (20%)
MMP Health (mobile):              XX/100  ███████░░░  (10%)
Cross-Device / Customer Match:    XX/100  ██████░░░░  (5%)

Deliverables

• ATTRIBUTION-AUDIT.md: Full surface-by-surface findings
• Cross-channel attribution map (which platform owns which conversion

windows + which events)

• Modeled vs reported conversion delta (estimated revenue under- or

over-attribution)

• Quick Wins sorted by signal-recovery $ impact
• Pre-launch checklist for any new platform (Amazon, Apple Ads, TikTok)

to ensure attribution is wired before spend begins