A small piece of code added to a website that tracks user actions and measures conversions, conversion value, or other metrics. These may be a JavaScript code, or it could be implemented as a small, invisible image pixel.
Ad platforms use these conversion tracking codes to understand which users were exposed to or engaged an ad, and ultimately performed conversion behavior on your website. This is accomplished by understanding which unique ID (assigned to the person) was exposed to ads. If the same ID is seen converting, a conversion can be measured.
Leveraging conversion tracking tags is a crucial technique that unlocks optimization for goal behavior, or goal value.
The website is responsible for triggering conversion tags based on users completing goal behavior. The way conversions are attributed to campaigns, ad groups and ads that participated in the user’s conversion path will vary based on the ad platform’s attribution model.