We are thinking of implementing the 3rd party id and setting it to = the users UUID regardless of authentication state.
Here is the issue;
When user first enters site from new computer or after clearing cache for example we assign a UUID that is essentially for a new user. When user authenticates we look to see if the UUID on the client side is the same on the account. If not then the local UUID is overwritten with the one attached to the account.
That means users might come onto site with PCID=1234 and mBox3rdPartyID(same as internal UUID)= ABC, but after authenticating the PCID = 1234 and now mBox3rdPartyID(now the one tied to account) = XYZ.
With that said, will the profile info captured with mbox3rdparty= ABC be merged with mbox3rdpartyid = xyz since they have the same PCID?
Additionally, let's say you started on desktop and your PCID = 123 & mbox3rdpartyId = ABC, now you go to mobile and your mbox3rdpartyId = abc, what will my PCID equal? Reason I ask is because initially you will be looked at as a new user but because we have a persistent UUID that as long as you authenticated once on the site from that device and haven't cleared cookies will be the same values.
The goal is to be able to make sure we are persisting profile info from one PCID to another as long as mbox3rdpartyid's match and that in the cases where a user comes to our site with one uuid(mbox3rdpartyid) that if it changes we will be able to merge profiles AND if there's any existing profile info in the authenticated version of the UUID(mbox3rdpartyID) that it will be available once again.