Unique visitors are the total number of individual visitors who visit a website in a given time interval.
In counting unique visitors, duplicate visits are obviously not taken into account, that is, one visit per individual user is considered.
Thanks to web analytics solutions, such as Google Analytics, it is possible to easily keep track of Unique Visitors as the tracking is done automatically by the system using persistent cookies, i.e., not subject to expiration.
This way if a user visits a website once and later re-enters it after closing the browser, it will still only be counted once.
Thus, we can say that unique visitors can be identified by the sum of all unique persistent cookies counted in a given reference period.
In addressing the topic of counting unique visitors, we cannot fail to consider the fact that since we are dealing with browser cookies, situations may occur such that some data is inaccurate.
This most commonly occurs when:
- the user navigates the site in incognito mode;
- clears cookies on the browser;
- accesses the same site through multiple devices;
- accesses the same site through multiple browsers available on the same device.
However, these are rather borderline cases and therefore the count offered by analytics services can be considered absolutely reliable.
