<i>The fingerprint is a hash of the visitors IP, User-Agent and a salt.</i><p>So the fingerprint is not unique for vistors from a corporate network behind a NAT router where multiple individuals share the same public IP and use the same corporate mandated browser. In these cases, it's back to cookies --- unless you don't really care if your analytics are faulty or not.<p>Or maybe just stick with cookies since it works in almost every case.