Users and sessions are defined differently in different platforms such as Google Analytics. This article describes how Dynamic Yield defines users and sessions.
A visitor who enters a site that contains the Dynamic Yield script is given a unique DYID. The DYID is stored in cookies, session storage, and local storage of the browser.
The DYID is not a 1:1 identifier for users, who are assigned a new DYID if any of the following happens:
- The user uses a different browser or a different device.
- The user deletes their cookies, cache, and local storage of the browser. Clearing the cookies and cache alone is insufficient, because they are restored by the local storage as soon as the user visits another site with the Dynamic Yield script.
- The user enters the site using incognito mode. If multiple incognito windows are opened at the same time, the user will get the same DYID in each of the windows.
Users are considered identified users when they are identified with a User ID, for example, through an event (say, login or subscribe to newsletter) that includes the user ID (say, an email address). In the audience explorer and in audience reports, identified users are considered once, even if they were assigned multiple DYIDs.
A session begins when a user enters a domain with the Dynamic Yield script. When measuring session stickiness and frequency, a session ends after 30 minutes of inactivity on your site, or if the user deletes their browser’s cookies and cache. When attributing conversions to a particular session, the session ends if the browser (all tabs) is closed, after 2 hours of inactivity on your site, or if the user deletes their browser’s cookies and cache.
Note: In Dynamic Yield, as opposed to Google Analytics, a new session does not automatically start at midnight. This ensures that late-night site visitors are tracked more accurately.
However, for session stickiness and frequency settings, sessions begin when a user enters a site with the Dynamic Yield script, and end when the browser is closed or after two hours.
Impressions are the serving of a variation (or the control group). Meaning, once a variation is served, an "impression" is fired. It doesn't necessarily means that the user actually viewed it (e.g. if the variation is at the footer, below the fold, and the user did not scroll).
This metric is also used to calculate CTR, which is the total number of clicks divided by the total number of impressions. Note that CTR is not Unique CTR (i.e. if a user was served with the variation 3 times and clicked it twice, the CTR will be 66.7%).