Webtrends Analytics 9 Adminstration Guide, November 2012
Consider the following domains:
All of these domains are subdomains of the root domain www.webtrends.com. Therefore, in the Webtrends Analytics 9 user interface, you would specify .webtrends.com (note the leading period) to track cookies across these domains.
Also, note that another domain such as www.webtrends.store.com can be a separate root domain that belongs to the same Webtrends account. Using Webtrends cross-domain tracking, the same visitor ID can be moved from one domain to another. This is because Webtrends Analytics 9 can recognize that all four domains are members of the same account (Webtrends).
You can specify the domain for your cookie when you add or edit a data source.