The next report in the Visitor Trending section is Absolute Unique Visitors. An absolute unique visitor is one what has not been to your site before during a specified time period, as determined by cookies. Keep in mind there are other factors such as deleting cookies, multiple computers and browsers used by one person and multiple people using the same computer, which can influence the accuracy of visitor reports. As long as we understand these nuances, we’ll understand what we’re looking at, and most importantly, we use Analytics to analyze trends.
Remember no analytics solution is 100% accurate, and they’ll all be either over or under the true values. Looking at data trends over time minimizes this effect.
This report, found under Visitor Trending in the left side menu, counts visitors to your website during the selected date range. In this report Google is counting each “unique” visitor to your site just one time each for the selected date range. One count per person.
An example should help clarify this report.
Fred views your site once a day for a week. Unfortunately he is your only visitor that week.
You view the Absolute Unique Visitors report for that week in Google Analytics and you have 1 Absolute Unique Visitor (Fred).
He may have come 7 times, but each person is only counted once (assuming Fred kept clear of the Delete Cookies button). The other 6 times Fred is a returning visitor, but that is the new vs. returning visitor report. So your report would show one absolute unique visitor for the week you are viewing.
The next week Fred has told his friend Mary about your site and she visits on Sunday. Fred loves it so much he has come back again every day.
This time when you view the report for this week alone, you will see 2 Absolute Unique Visitors. Even though between them they had a total of 8 visits, they were each unique visitors for only one of those visits.
To recap, the Absolute Unique Visitors report is going to provide you with the number of individual visitors that have visited your site during a given time period regardless of the number of times they have visited. It is important to remember that this is specific to the date range you set for the report.