is the FPID required for first party tracking

Hi ​@Michael_Soprano 

these are two things.

FPID

• a FPID service is running on your own web servers
• returns a true first-party cookie which lifetime cannot be limited by any browser

Hence you do not need a CNAME domain for the FPID service to work.

CNAME 

• a subdomain through which you send your Edge network requests which in their response Adobe returns a presumably first-party cookie (kndctr cookies)
• without the CNAME, the lifetime is heavily restricted since it is a third-party cookie
• NOTE:
  • with the CNAME, most browsers accept it as first-party cookie
  • however some browsers notice that the receiving IP behind your CNAME is Adobe and not your own website, and still treat it as third party cookie with limited lifetime  (e.g., through Safari’s ITP).

Best practice should always be aiming for a FPID cookie which you can then also make use of in other marketing pixels and server-side forwarding (CAPI) for better user identification.

Note though, that this user identification underlies the usual cookie consent limitations i.e., your FPID cookie must be categorized as for instance “Analytics or Tracking” cookie and the use is restricted to the given consent.