Full Answer

The cost breaks into three layers. Collection requires a custom WordPress plugin that hooks into WooCommerce events — woocommerce_payment_complete, woocommerce_add_to_cart, woocommerce_checkout_order_processed — and formats each event with consistent schema, attribution parameters, and hashed customer identifiers. A production-grade collection plugin is 80–120 hours of WordPress development.

Processing requires a server-side application — typically Node.js — running on your infrastructure to receive events from the plugin, validate them against a schema, deduplicate concurrent events, and queue them for delivery. This layer handles retry logic for failed API calls, rate limiting for destination APIs, and logging for debugging. Building this from scratch is 120–200 hours of backend engineering.

Delivery requires separate integration code for each destination. BigQuery uses the Streaming Insert API with specific authentication, schema mapping, and error handling. GA4 requires the Measurement Protocol with its own payload format. Facebook CAPI requires SHA256 hashing of customer identifiers and event_id deduplication. Google Ads Enhanced Conversions requires yet another payload format. Each destination adds 30–50 hours of integration and testing.

Ongoing maintenance compounds the cost. Destination APIs change — Meta updates CAPI requirements, Google changes Measurement Protocol specifications — and each change requires developer time to update, test, and deploy. A single developer spending 10 hours per month on pipeline maintenance costs $14,400–$21,600 annually. The total five-year cost of a custom pipeline ranges from $105,000 to $280,000.