[rpicard]

Wouldn't the chance get higher and higher as the service expands? It seems as though there would be more existing fingerprints that might collide.

[dmitrig01]

Dmitri from Branch here. When a user has already had a fingerprint matched once, we can do future matches with much higher certainty, so as more and more users click links and are matched, the chance decreases.

Additionally, as Alex said, though most uses of the links don't require a 100% match rate ("any growth is good"), we do have an option for links which require a 100% match.