By default we identify user who log into their accounts automatically.
However this is not possible all the time, mostly because of credentials saved in the browser, or usage of extensions like LastPass or 1password.
To circumvent this potential miss of real users who are logged in into their account you need to add the following code, to every page you have access to user email address:
window._vteq = window._vteq || ;
window._vteq.push(["setVar","VTuser", "[email protected]"]);
Identification using VTuser variable can only be done by email address for the moment.