Case: HTTP postbacks were failing silently — 7% of conversions lost

Case: HTTP postbacks were failing silently — 7% of conversions lost

The setup: Keitaro on HTTPS, an older offer network firing postbacks to an http:// endpoint. Conversions arrived but the count was always slightly low versus the network's report.

How we found it:
1. Pulled the tracker's incoming-request log, filtered for the postback path
2. Cross-checked against the network's conversion export for the same window
3. 7% of network conversions had no matching tracker request at all — the postbacks were being dropped before they hit the log
4. The dropped ones correlated with a redirect from http to https that the network's server didn't follow on POST

The fix:
— Gave the network an explicit https:// postback URL (no relying on redirect)
— Switched the postback method to GET, which the network's caller followed cleanly
— Re-tested with a forced conversion and confirmed it logged

Outcome: the 7% gap closed to under 1%. On a campaign doing 900 conversions/month, that was 60+ recovered without spending a cent more.

Networks rarely follow redirects on server-to-server postbacks. Hand them the final HTTPS URL directly.

Save this SOP. Run this before every launch.