How can I track multiple sites so that visitors can go to both sites at the same time

Acoustic Campaign only appends the webSyncID variable to page URLs when the destination URL is different from the current page domain and is registered as a domain that needs to be tracked. The webSyncID must be passed along to the next site domain in order for that domain to add behaviors/events to the same contact. If a visitor clicks a link on SiteA that goes to SiteB which is not having the webSyncID will cause the visitor to look like an anonymous visitor on siteB.

We use first person cookies, which means siteB.com can not read the cookie set for the same contact on SiteA.com. This is the safest and preferred cookie standard. We pass the visitor id along to the various sites the customer is tracking in order to associate all the visitors behaviors with a single contact in Acoustic Campaign. The websyncid passed to siteB will cause the SiteB cookie to get set to the same value as the siteA cookie - both of which map to a single contact in Acoustic Campaign.

Keep in mind, if a visitor goes to siteA and then closes the browser and later goes directly to siteB, Acoustic Campaign will not recognize this as the same visitor. However, as soon as the person identifies themselves (say by submitting a form, or because they got a Acoustic Campaign email that sent them to a site) we will associate the behavior of that site to the person's contact record.

Visitor goes to siteA and submits a form - site A web tracking is now associated with that visitor. The same visitor goes directly to siteB (no link from siteA) a month or so later. SiteB stores the visitor's behaviors anonymously. If the visitor then submits a form on site B - the record will get matched in the database say on email - and we will recognize that this is the same person who was on site A and associate the behaviors from both sites to the same contact. Also keep in mind, the main reason for adding a listing of all the domains a company has in the Web Tracking code is so that we can know when to add the webSyncID to any links on the page that are pointing to another tracked site. If the customer is not actually linking the sites together, there is no value in adding them to the meta tag. In the above scenario, where I have tracking on two sites that do not have links pointing to each other, the visitor can still have the behaviors associated together - assuming they submit a form on both sites or visit the sites through Acoustic Campaign email.

A single contact in Acoustic Campaign can sometimes get associated to multiple cookies if each site they visited set the cookie before it was associated with cookies from other tracked sites for a given customer. This is an okay outcome and Acoustic Campaign will associate the various cookies to the same contact as each one gets identified (submit a form, visit site from email).

If you are using Acoustic Campaign hosted forms, then no custom programming work is needed. If the forms are not externally hosted, then you will need to write the code that reads the ID of the cookie and pass it along with your form submit or the API call that you make. This way, Acoustic Campaign can connect the anonymous visit behaviors with the new or updated record you create through an API.