Before Campaign 8.8 Release, the cookies created to keep track of visitor identity and session were stored at the domain of the URL. If a customer went to marketing.goacoustic.com the cookies would be stored at the domain marketing.goacoustic.com. Beginning with the Campaign 8.8 Release, the web tracking code is updated. By default, if you have multiple sub-domains belonging to the same primary domain and use web tracking code on your sites, visitors to your subdomain pages will no longer see the query string parameters in the URL. This means when visitors to your site go to one of your subdomain pages, they will only see your primary domain's URL.
If a visitor goes from marketing.goacoustic.com to someCoolDomain.goacoustic.com via a link in the web page, the web tracking script appends the 'webSyncId' and 'SessionGUID?' parameters to the query, even though the primary domain is the same.
Some users may find a problem with this approach because they may want the cookies stored at the subdomain. If you want to override where the cookies are being written and have your cookies stored at the subdomain, you can add a META tag to your web page and specify the domain.
name='com.goacoustic.primary_domain' content='sub1.myDomainGoesHere.com' />