Hi I believe I understand that we can track visitors across domains
using CNAME or Visitor.appendVisitorIDsTo - via a first party cookie But
what I don't get is, is this tracking relegated to my domains? E.g.,
mysite.com and blog.mysite.com and uk.mysite.com Or can I also use
Visitor.appendVisitorIDsTo to track across nike.com, bestbuy.com,
target.com, etc. And in either case, is this profile info permanent? Or
does it expire after 1-7 days (per cross device analytics) or after
6-months if using...