1) how can I best collect my own customer/ user ID? Should this be in an evar and what should be the settings of this evar (also with GDPR in mind)?
2) if for this customer the real conversion takes place in a back-end application, what can be used to link this conversion to the same visitor for Adobe Analytics?
Thanks for your reply.
With respect to the second question, can I make use of the following documentation?
If I am correct using POST or GET you need to provide <visitorid>, <mcid> or <ipaddress>. If I use the (the client's) customer ID for the <visitorid>-field and use customer ID in the right eVar field I should be able to connect the "purchase", however during the client-side process Adobe reports on visitorId or MCID and not on the client's customer ID. So, for Adobe Analytics I have two different visitorIDs for the same customer ID. Is this assumption correct?
If you wanted to make the purchase event seamless with the rest of the customer's visit, you would want to make sure the visitor ID or MCID matched the value stored in the Analytics cookie (which one you use would depend on which one is currently being used in your implementation). This means you would want to pass that cookie value to your server, so the server can send the image request to Adobe's data collection servers.