All visitors to your tracked pages are initially treated as anonymous. They are all assigned a unique number so you can see who is a returning vs. a new visitor:
Visitors become "known" (sometimes referred to as being "tracked", "identified" or having a "session") when they:
- submit a tracked form;
- respond to a Proactive Subscribe or Proactive Reply Back Headsup message;
- click on a link in an email you send from Autopilot;
- are identified via the user association method; or
- are identified via the API (see the section titled "Associating Sessions").
When a visitor becomes known, all of their previously anonymous activity, as well as their future activity, will be associated with either a new or existing contact; this is decided based on whether a contact with the email provided already exists. For this reason, you must supply an email address in order for a contact to be created for a known visitor.
For example, let's say the anonymous visitor in the screenshot above submitted a form:
Notice that the previously anonymous visit is now associated with Peter.
Please note that tracking relies on cookies, so if a contact clears their cookies, they will be treated as anonymous until they become known again via one of the above methods.