An API is an Application Programming Interface. API postbacks and pixel postbacks, also known as server-to-server postbacks, are a method used in affiliate marketing to track conversions and attribute them to the correct affiliate.
They work by using a server-to-server connection, which allows the advertiser’s website to communicate directly with the affiliate network’s server, passing along information about conversions in real-time.
When a user completes a conversion on an advertiser’s website, the advertiser’s server sends a postback to the affiliate network, passing along information such as the affiliate’s ID, the conversion amount, and any other relevant data. The affiliate network then attributes the conversion to the correct affiliate and updates its statistics accordingly.