Postback
Also called S2S, Server-to-server tracking.
A signed server call from the advertiser back to the tracker saying a conversion happened.
Postbacks exist because browser-side conversion tracking is unreliable: pixels get blocked, cookies get cleared, and Safari and Firefox restrict cross-site state by default. A server call from the advertiser's backend survives all of that.
Postbacks must be signed and must reject replays, or they are an open endpoint that anyone can use to invent conversions the publisher gets paid for.
How LinkBourse handles it
Conversion postbacks are HMAC-signed and time-bounded; an unsigned, stale or repeated call is rejected rather than counted, so neither side can inflate the number the escrow releases against.
Terms it depends on
- CPA
- A price paid per completed action — a sale, a signup, a booked demo — rather than per click.
- CPL
- A price paid per qualified lead — a form fill, a trial start, a booked call.
- Attribution window
- How long after a click or view a conversion still counts as caused by that ad.
- UTM parameters
- Tags appended to a destination URL so the advertiser's own analytics can attribute the visit.