Why do seven daily unique counts not add up to the weekly one?

Someone active on several days is counted on each of those days but only once across the week. The weekly figure is always less than or equal to the sum of the daily ones and has to be computed directly on the weekly range.

Unique event users vs. event count?

Event count says how many times the action happened; unique users says how many people did it. Volume rising without unique users rising means the same small group is repeating the action, not that the feature reached anyone new.

Unique Event Users

Intermediate

Updated Jul 11, 2026 Shahin editorial 3 min read

PronunciationEN/juːˈniːk ɪˈvɛnt ˈjuːzərz/

Unique event users is the number of distinct people who performed a given event at least once in a time range, however many times each of them repeated it.

The count deduplicates by identity inside the chosen window, so one person performing the action thirty times still counts once. Read next to event count, the pair answers two different questions: event count is volume, unique event users is reach, and dividing one by the other gives events per user, which is usually where the story sits. Two properties of the number surprise people. Unique counts are not additive, so seven daily figures do not sum to the weekly figure, and one person using a phone and a laptop without signing in counts as two users.

How it is calculated

Unique event users = count of distinct user identities that recorded the event at least once in the selected range

Distinctness is by identity: the user id for signed-in people and the anonymous device id for everyone else. The unit is people, not events, and the number is not additive across ranges.

How it is calculated

FAQ