Unique Users (UUs)

Unique Users

A unique user i.e. unique visitor on a website is a user counted only once no matter how many times they visit the site over a set period of time. Counting the number of unique users on your website accurately is a challenge for any web analytics consultant. Utilizing cookies is one option as is checking user IDs or any log in information available. Combine the data available to get the best estimate of unique user data possible.
Note that when doing access analysis on mobile phones, the measurement standard for sessions and unique users differs from program to program.

Differentiating unique users from the number of sessions recorded

The number of sessions recorded by analytics software reflects how often a single unique user visits a specific website from their browser over the course of a set period of time.

Information you can gather from analyzing unique users

This data is used to measure the popularity of a website. If the number of unique users increases, that means that there are more new unique users browsing your website.

A new unique user (i.e., a new visitor)

A new unique user or new visitor refers to a user who has visited a website for the first time. Since cookies are used to determine whether it is their first visit or not, you cannot tell a new unique user from a repeater with 100% accuracy.

Companies can increase or change their publicity campaigns to attract new customers and new unique users.

What is the new unique user rate?

The new unique user rate or new visitor rate is calculated by dividing the number of unique users who visit a website for the first time by the number of all unique users counted during the period being analyzed.

What is a returning visitor?

A returning visitor is a user who has visited the website before. Again, cookies are used to determine whether it is a return visit. Note that you cannot identify a returning visitor with 100% accuracy. Returning visitor statistics increase as the number of users revisiting a website grows.

Notes on Unique User Analysis

・ Note that the number of unique users is not the total number of visitors.

Assume that users A, B, and C visited a website in January and then the users B and C revisited the website in February. In this case, the number of unique users for the month of January and February would be “three” and “two,” respectively. Note that the number of unique users for the two months of January and February combined would not be “five” but “three.”

・ For a measurement method that uses cookies, accesses from a single user using different browsers are recognized as different users, and the number of unique users increases by the number of browsers used. Also, if a user erases the cookie, they will be counted as a new user on their next visit to the website.
・ The number of unique users cannot be counted correctly through measurements based on the IP address alone (e.g., using a server-installed analysis tool).
・ When browsing a website from a PC which does not accept cookies, sessions are disconnected each time the user moves between pages. You may not be able to track a series of activities done by a unique user.

Notes on Repeater Analysis

You will encounter the following problems when you try to count unique users and repeaters using an access analysis tool:
・ A user who visited the website before the access analysis tool was installed will be identified as a new unique user.

・ If a user erases the cookie accepted from the website from a previous visit or their security software settings do not allow for the acceptance of cookies, they will be identified as a new unique user on their next visit.

・ A user whose cookie has expired will be identified as a new unique user.

For online shopping support services, new purchasers and returning purchasers may be recorded in a different method from access analysis tools. Note that the terms “new” and “repeat” may have different meanings between the order history information and access analysis information.

Notes on Analyzing Unique User Ratio

The sum of the “new unique user rate” and the “repeat unique user rate” does not equal 100%. In the figure shown to the right, the new unique user rate is 50%, while the repeat unique user
・ The new session rate uses a similar index but the calculation method differs between analysis tools and it needs to be checked.