Editing Email Campaigns (section)

=== How Google Analytics sessions are tracked ===
Google Analytics logs JavaScript-enabled pageviews that result from campaign link clicks. A session in Google Analytics is a group of interactions (page views, events, social interactions, and a transaction) that take place on your website within a given time frame. A single contact can have multiple sessions, which can expire after 30 minutes of inactivity.

In Google Analytics, several things happen before a session is finally loaded. When a campaign link click occurs, the browser is pointed to your landing page. Your website then responds to this request and transfers data from the web server to the contact's browser.

When the browser starts to download the landing page, there may be a request for several files simultaneously. This includes JavaScript, CSS, images, video, audio, and more. The requests for JavaScript include the Google Analytics tracking code. The contact's browser and security settings must support cookies, JavaScript, and images. If any of these are disabled, Google Analytics may be unable to record a session.

Then, the contact's browser sends a separate request to the Google Analytics servers, and the session is recorded.