Re: Is cross domain tracking affected when user-id is enabled?
No, you need to send user-id (this id defines by your side) and client ID will still be defined by GA side.
User-id helps to connect all user's actions on different devices or browsers (has different client IDs).
Is cross domain tracking affected when user-id is enabled?
I am curious about this also, but have a slightly different question. In the case where a user's session crosses domains and cross-domain tracking is enabled, but the user id is passed only on one of the domains they visit in that session, will session unification still work?