Inconsistent user number in User Explorer
I got a web with User ID tracked. When I try to look at the User Explorer, it listed out around 6,000 unique User Ids. However, when I try to put the mouse at the segment "All Users", it says 46,xxx out of 46,xxx users.
May I know why there is such a difference? Is it because there are 40,xxx users without a User Id specified?