Thanks for your thoughtful comment! I was hoping for a little more dialogue, too... but so it goes.

Implementation would not be all that hard. Each user's ID is already part of the unique URL of every post... so all that's needed is a temporary tracking cookie tying a visitor's actions on Steemit to whatever username is in the URL they click on somewhere. It's a fairly standard way to track affiliate activity. The trick is creating a new database field that links a new member to the username within the post that brought them here.