For all experiences that run on the Monetate platform, a session is defined as consecutive activity on your site by one Monetate ID. A session expires after 30 minutes of inactivity but can persist for as long as 12 hours if a visitor is active at least once every 30 minutes.
To better illustrate this concept, consider the following example. A visitor arrives on your site using Google Chrome. This browser is assigned a Monetate ID and a new session begins. If the visitor spends 10 minutes on the site and then leaves, the session can persist for up to 30 minutes. If the visitor returns using the same browser and device after 15 minutes, Monetate treats this as a continuation of the earlier session. If the visitor doesn't return again for several days or if the visitor accesses your site from a different browser or device, Monetate treats the next visit to the site as a new session.
The length of a session and the metrics that rely on it it for their calculation can vary from one analytics platform to the next. Some define a session as a segment of time that ends after 30 minutes of inactivity. Others use an hour. Keep this difference in mind when you compare data from third-party analytics platforms with the experience reports that Monetate provides. It's highly unlikely that each report will match with precision.