Full Answer
Why numbers never match: 1. Attribution models differ:
- GA4: Last non-direct click (cross-channel)
- Facebook: 7-day click, 1-day view (Facebook-centric)
- Google Ads: Last Google click (Google-centric) 2. Attribution windows differ:
- GA4: 30-90 day lookback
- Facebook: 7-day click default
- Time between ad click and purchase affects which platform counts it 3. Tracking blocked differently:
- Ad blocker blocks GA4 but user converts: FB has it, GA4 doesn't
- Safari ITP affects all, but timing varies 4. Processing delays:
- Real-time vs daily batch processing varies by...