Conversions API
A server-to-server path for sending conversion events to an advertising platform, alongside or instead of the browser pixel.
What makes it wrong.
The mechanism, not the warning.
Without a correctly propagated deduplication key, running both paths double-counts every conversion that both saw. The symptom is a platform conversion count noticeably above the order system's, with no obvious source.
In detail.
Events sent from the advertiser's own systems are not subject to browser tracking prevention, so the server path recovers conversions the pixel loses. It also allows sending events the browser never sees, such as an order confirmed later in a back office.
Running both paths is the normal configuration, with a shared event identifier so the platform can recognise the two reports as one event.