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
- 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
- Read
ads/references/conversion-tracking.md for the cross-platform
tracking baseline
- Evaluate attribution health per surface (web, iOS app, Android app,
server-side)
- Score each surface PASS / WARNING / FAIL
- 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
| Metric | Pass | Warning | Fail |
|---|
| GA4 attribution model | Data-Driven | Last-Click (intentional) | Last-Click (residual) |
| Consent Mode V2 | Advanced + verified | Advanced (unverified) | Basic / Not implemented |
| EMQ (Meta Purchase) | ≥8.0 | 6.0-7.9 | <6.0 |
| Event dedup rate | ≥90% | 70-89% | <70% |
| Server-side / client-side hit ratio | ≥80% | 50-79% | <50% |
| ATT opt-in (iOS) | ≥30% | 15-29% | <15% (heavy SKAN reliance) |
| Offline conversion import latency | <24h | 24-72h | >72h |
| Customer Match list freshness | <7 days | 7-30 days | >30 days |
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