Postback (S2S) conversion tracking: how it works and how to set it up

If you buy traffic for performance, you need to know which clicks turn into results. Postback is the most reliable way to send that information back to the ad platform. This article explains how it works and how to set it up.

What is a postback?

A postback is an HTTP request that your server or tracking software sends to the ad platform when a conversion happens. It carries a click ID that ties the conversion to the original click — and through it to the campaign, placement, GEO and creative.

Because the request goes server to server, it does not depend on the user's browser, cookies or ad blockers.

Postback vs tracking pixel

How does postback tracking work?

1. The click. A user clicks your ad. The platform opens your landing page and adds a click ID to the URL, for example https://your-site.com/landing?click_id=abc123.
2. Storing the ID. Your site or tracker saves click_id with the user's session.
3. The conversion. The user signs up, buys or installs.
4. The postback. Your server calls the platform's postback URL with the stored ID, for example https://postback.example/?click_id=abc123&payout=10&status=approved.
5. Attribution. The platform matches the ID to the click and shows the conversion in your statistics.

The parameter names above are only examples. Each platform has its own macros — placeholders that it fills with the real values — so always use the exact template from your dashboard.

What can a postback carry?

• Click ID — required, links the conversion to the click.
• Payout or revenue — lets you see return on ad spend.
• Status — approved, pending or rejected, if conversions are confirmed later.
• Event type — registration, first deposit, purchase, if you track several steps.

How to set it up, step by step

1. Get the postback template and click ID macro from the ad platform.
2. Add the macro to your campaign URL so each click arrives with an ID.
3. Make sure the ID survives redirects and is stored in your tracker or database.
4. Configure the postback in your tracker or backend to call the platform's URL on conversion.
5. Test with a real click: click your own ad (or use the platform's test tool), complete a conversion and check that it appears in the statistics.
6. Monitor discrepancies between your tracker and the platform. Small differences are normal; large ones mean an ID is being lost.

Common mistakes

• The click ID is dropped by a redirect between the ad and the landing page.
• The wrong macro is used in the postback URL, so the platform receives a literal placeholder instead of the ID.
• Duplicate postbacks for one conversion inflate results.
• Postbacks sent before validation, then never corrected for rejected conversions.

Why postback matters for optimization

With conversions tied to each placement, you can build black and white lists, compare GEOs and creatives and spot fraud: placements with many clicks and no conversions stand out at once. See ad targeting options and ad fraud and traffic quality.

Postback with Wizads

The Wizads DSP supports postback (server-to-server) conversion tracking: you send conversions from your tracker or website back to the platform to measure and optimize campaign performance. The postback template and click ID macro are available from your dashboard or your personal manager. Partners can also export statistics through the Wizads API.

Frequently asked questions

Do I need a tracker for postback?

Not necessarily. A tracker makes it easier, but any backend that stores the click ID and makes an HTTP request on conversion can send a postback.

Can I track several events?

Yes, if the platform supports event types or separate postbacks per goal. Track the event closest to revenue as your main optimization goal.

Where do I learn the rest of the campaign setup?

Our guide to buying website traffic covers formats, targeting, bids, testing and scaling.