Probabilistic ID is a complete opposite of deterministic ID. It is based on algorithms, a lot of them as a matter of fact and it is completely anonymous. It uses operating system version, device, behavior, and location which is then submitted through series of algorithms in order to get the proper data.
Probabilistic ID technology started its life back in 2014, although it was designed a few years earlier. The first major company to use it was Microsoft. Nowadays, it is widely used and it has been developed to perfection.
This form of targeting or acquiring data, more precisely is essential for creating reports and analyzing how much a specific action, feature or system is used by actual users. The accuracy will depend on the set of algorithms used, so it cannot be defined to perfection.
How many users prefer a certain thing or a service will be answered with the use of the technology in question. Affiliate marketers can use it in order to offer the ads which are specifically optimized for the targeted group of users or better said to understand why the audience actually wants.