Platform Reporting Discrepancy

Platform reporting discrepancies are the #1 source of confusion for ecommerce marketers. Common scenarios: Meta Ads Manager shows 6x ROAS, Shopify shows 4.2x ROAS from Meta traffic - which is correct? Google Ads reports 150 conversions, GA4 shows 120 conversions - where did 30 go? Root causes: Attribution windows (Meta 7-day vs Shopify 30-day last-click), View-through attribution (Meta includes 1-day VTA, Shopify doesn't), Time zone mismatches (Meta reports in PST, Shopify in your local time), Conversion counting (Meta counts at checkout, Shopify at order completion), Return/refund handling (platforms don't update, Shopify does), and Invalid traffic (bots counted by platforms, filtered by Shopify). How to diagnose: Export data from both sources for same date range, Align time zones (convert all to UTC or your local time), Compare conversion counts (platform vs Shopify), Calculate revenue difference (platform vs actual), and Identify patterns (consistent % gap or sporadic?). Typical findings: Platforms over-report conversions by 15-35%, Platforms over-report revenue by 20-40%, and VTA accounts for 30-50% of the gap. How to report accurately: Use Shopify revenue as source of truth (actual money received), Calculate true ROAS (Shopify revenue ÷ platform spend), and Document discrepancy (explain gap to stakeholders). CFO best practice: Always report Shopify numbers, not platform numbers. Platform ROAS is for optimization, not board reporting.