When you sign up to an Analytics Plan you are given the option to specify the email addresses of the Analytics Users. You are also given the option to treat the email address of the subscription account holder as an Analytics User (this is ticked by default).
You can update either of these from the subscription portal. From the subscription portal Home page, click 'View More'.
Click the edit icon in the Account Details section.
The 'Email is Analytics User' refers to the email address that is used to log into the subscription portal. You can check or uncheck this as needed.
The semi-colon separated list of Analytics User email addresses is like the 'To' line of an email. Each user in the list will receive an invite to Open Data Blend Analytics and their activity will be linked to your subscription.
If an email address is already linked to another Analytics Plan subscription, only the link to the active subscription that was created first will be honoured for billing purposes.