Full Answer

Each Conversion API solves a specific attribution gap created by browser restrictions and iOS privacy changes. Facebook CAPI sends purchase events server-to-server when the Pixel cannot, which is critical for iOS users who have opted out of tracking. Google Ads Enhanced Conversions supplements standard conversion tracking with hashed customer data (email, phone), improving Smart Bidding match quality. GA4 Measurement Protocol fills event gaps where browser scripts are blocked, ensuring complete funnel data. TikTok Events API mirrors CAPI's function for TikTok ad campaigns. Klaviyo's Track API connects purchase events to email automation sequences.

For WooCommerce stores running multiple ad channels, connecting all APIs simultaneously from a single server-side pipeline eliminates redundant plugin installs, reduces WordPress overhead, and ensures event deduplication across platforms. Stores on single-channel ad spend can prioritize their primary platform first and add destinations incrementally.