Conversion tracking: click IDs, postbacks and attribution

Reliable tracking is the foundation of performance marketing: if a conversion is not recorded against the right click, nobody can be paid correctly and nobody can optimize.

The building blocks

• Tracking link — the URL publishers use; it records the click and redirects the user.
• Click ID — a unique identifier generated per click and passed to the advertiser.
• Sub-IDs — publisher-defined parameters (sub1…sub5) for placements and creatives.
• Postback URL — the endpoint the advertiser calls when a conversion happens.
• Attribution window — how long after a click a conversion can be credited.

Step-by-step setup

1. Capture the click ID. On your landing page or in your app's attribution flow, read the click ID from the URL and store it with the user's session or record.
2. Persist it through the funnel. Keep the click ID attached as the user registers, checks out or installs.
3. Fire the postback server-to-server. When the conversion happens, call the network's postback URL from your server with the click ID and event details.
4. Handle duplicates. Ensure one conversion fires one postback, and that retries are idempotent.
5. Secure the endpoint. Use a secret token and, where possible, an IP allow-list.

Example postback:

GET https://track.example.net/postback?click_id={click_id}&event=purchase&value={order_value}&currency=EUR&token={secret}

For mobile apps

Apps typically use a mobile measurement partner (MMP). The MMP attributes installs and in-app events and sends postbacks to the network on your behalf. Configure which events are forwarded, and use the same event names on both sides.

Testing checklist

• A test click generates a click ID visible in the tracking system
• The click ID reaches the landing page unchanged (check redirects and URL encoding)
• A test conversion fires exactly one postback
• The postback is matched to the right publisher and sub-ID
• Currency and value are correct
• Duplicate conversions are rejected