Views per viewer

Studio shows it in the Audience tab as average views per viewer. Unique viewers is an estimate built from signed-in and signed-out traffic across devices, and YouTube limits the metric to windows of 90 days or less.

Both halves of the sum depend on the window you pick, so the figure climbs the longer the range. A seven-day number and a ninety-day number answer different questions and comparing them tells you nothing. Track it on one window over time. A rise means people who find you are choosing to watch a second and a third video, which is the thing subscriber count keeps failing to tell you.