This is a tracking method used for tracking specific devices and multi-screen users. It is based on the fingerprint technology and algorithms. In essence, it is used without cookies and it is based on probability.
This is relatively new technology and we must add that it has been used during a couple of years back. The main reason for that is in the fact it is based on mentioned fingerprint technology, which was mass implemented in 2013.
For all marketers, this technology is essential. It is one of the best methods for targeting the devices that are used and identifying which ones are actually more common, which is therefore essential for multi-screen advertising.