Conversion event
A tracked action promoted to the finish line, such as a completed purchase or booked demo, so analytics can count success.
See it
What it is
A conversion event is an ordinary tracked event that you designate as a wanted outcome. 'checkout_completed', 'demo_booked', and 'subscription_started' can all be conversion events. The designation does not change the raw event; it tells reports and ad tools which actions should count as success. GA4 renamed its version key events in 2024, and the Meta pixel calls the same idea a standard event, with reserved names such as Purchase and Lead.
Reach for one when a funnel, campaign, or landing page needs a finish line. Name the completed outcome, then fire it where the outcome becomes true. A payment success webhook is a better source for 'purchase_completed' than the checkout button, because clicks can fail and retries can succeed without another click.
Gotcha: one real outcome must become one counted event. Browser refreshes, webhook retries, and duplicate SDK calls can turn one order into three conversions. Carry a stable order or event id, deduplicate on it, and keep micro-actions such as button clicks as regular events instead of declaring everything a conversion.
Ask AI for it
Instrument a 'checkout_completed' conversion event from Stripe's 'checkout.session.completed' webhook using the PostHog Node SDK. Verify the Stripe webhook signature, use the Stripe event id as an idempotency key, and emit only after the session reports payment_status='paid'. Attach order_id, value, currency, plan, and campaign properties, but no raw card or personal data. Add an integration test that delivers the same webhook twice and proves PostHog receives one conversion.