overwriteCrossDomainMCIDAndAID overwritecrossdomainmcidandaid
This property overwrites a visitor’s Experience Cloud and Analytics IDs as they navigate from one domain to a second domain. To overwrite an ID, you must own and have implemented the ID service on each domain. This code does not let you overwrite IDs on domains you do not control.
Syntax: Visitor.overwriteCrossDomainMCIDAndAID: true|false (default is false)
Code Sample
Your JavaScript code could look similar to the following example.
//Call the ID service
var visitor = Visitor.getInstance("INSERT-MARKETING-CLOUD-ID-HERE", {
...
//Set overwrite property
overwriteCrossDomainMCIDAndAID: true
});
Use Cases
To track site visitors, the ID service writes a Experience Cloud ID (or MID) to a browser cookie. The following table lists and describes the common use cases where you might want to overwrite an existing MID set by the ID service in another domain.
Let's say you own Domains A and B. In this case you can set Visitor.overwriteCrossDomainMCIDAndAID: true when:
- Each domain has a it's own landing page.
- A visitor already has a cookie (and a MID) set from a previous visit to Domain B.
- You want to consistently identify a visitor if they come to Domain B from Domain A.
Let's say you own Domains A and B. In this case, you can set Visitor.overwriteCrossDomainMCIDAndAID: true when:
- Domain A is a landing page.
- Domain B is a separate conversion, booking, or other end-of-workflow page.
- A visitor already has a cookie (and a MID) set from a previous visit to Domain B and you know these are less desirable client-side MIDs rather than server-side MIDs.
- You want to consistently identify a visitor if they come to Domain B from Domain A.