Understand information in your reports and troubleshoot reporting issues such as self-referrals, (not set) data, and inaccurate information
 
Guide Me
star_border
Reply

GA Sessions

Visitor ✭ ✭ ✭
# 1
Visitor ✭ ✭ ✭

In which cases the all sessions count doesn't match the session count summary when I add the Secondary Dimension userID?

All -> 1066

Summary -> 942

2016-04-29_16-39-06.jpg 

1 Expert replyverified_user

Re: GA Sessions

[ Edited ]
Explorer ✭ ✭ ☆
# 2
Explorer ✭ ✭ ☆

All will include the users to your site who haven't been assigned an User-ID. They could be unregistered users or the users who haven;t logged in when the user ID is assigned if this is the case.

Re: GA Sessions

Visitor ✭ ✭ ✭
# 3
Visitor ✭ ✭ ✭
We set user ids even new users (guest).

Re: GA Sessions

Rising Star
# 4
Rising Star
If you are not filtering out spam then this could be your reason for seeing fewer sessions when you add the secondary dimension of user id, spam never hits your site it uses the measurement protocol and goes directly to the GA server by passing your site altogether, so it will never be assigned a user id by your website.