Fingerprinting is a technique of assigning a unique identifier to individual user and groups or cohorts. There are many such techniques. These vary in complexity, reliability and, in some cases, legality. As the Internet has evolved since the dawn of the past century, so did the need, approaches, and challenges concerning creating reliable browser fingerprints.

Three main forces share a fascination with tracking, analysing and attributing user activity to a specific action or trigger: the Adtech industry, online Marketing and Product-driven organisations. These forces, driven by mostly different motivations, have one thing in common. To be effective, they need to find an individual in a seemingly random website interaction.