Tracking Multiple Domains

Tracking Multiple Domains

When you set up Analytics to track across separate domains, or when you set up Analytics to restrict tracking to a section of your website, you are making adjustments to how Analytics collects visitor data for your web property. To understand this, let's first look at a default Analytics setup for a site or web property.

By default, Analytics records visits to a given URL as a group. For example, if you set up tracking to your blog——visits to all pages and subdirectories to your site are collected and tallied as a unit. That way, when a user goes from one page on your site to another page on that same site, the Analytics reports show the following relationships:

  • navigation path between pages
  • total time on site—as a cumulation of time on pages
  • number of individual sessions and unique sessions (visits)
  • number of unique visitors

In addition, Analytics treats visits to separate URLs as unique and unrelated (except for referring links). This is how you would expect Analytics to work, since you would not want visitor data from one website to appear in the Analytics report for a separate, unrelated website.

Two profiles used to collect data from two separate websites

Now suppose that you have an online shop and a 3rd-party shopping basket hosted on another domain, such as:


Without cross-domain customisations, a visitor who first visits your online shop and then proceeds to your 3rd-party shopping basket is counted as two separate visitors with two separate visits of different durations, which is not appropriate for this model.

You can, however, use cross-domain tracking to make sure that Analytics records traffic to these two sites to the same report. In web analytics, this is often called site linking. With it, a visitor to your online shop who proceeds to your shopping basket is counted as one visitor - not two - and the session that they started in the shop is continued through to the time spent on the shopping basket.


One profile used to collect data from two separate websites