---
title: "Visitors, Yearly Unique"
slug: "visitors-yearly-unique"
updated: 2024-03-15T06:46:58Z
published: 2024-03-15T06:46:58Z
canonical: "docs.mapp.com/visitors-yearly-unique"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Visitors, Yearly Unique

Shows the amount of different visitors per year.

It is often used in analyses, that don't show a development over time (e.g. campaigns).

### Example:

A visitor accesses the website in October, November and December. He is counted only once (e.g. in the campaign analysis).

In case a visitor accesses the website in 2 years (e.g. December 2016 and January 2017), he is counted twice (once per year).

Visitors are identified either based on the cookie and/or a submitted customer ID.

> - Don't use this metric in time analyses, that show a smaller time interval than "Years" (e.g. "Days", "Hours"...). In this case the calculation is done automatically per used time interval.
> - If you use the metric in a year analysis (dimension "Years") double countings can occur. All users, whose visit lasted from December 31 to January 1 are counted again, when another visit is made in the year. In this case, use the metric "Visitors".