There are four main benefits of the User ID and this article will help you understand them.In this article:
Get a more accurate user count
Many analytics technologies can’t identify unique users across multiple devices or sessions. Each time someone switches to a different device or starts a new session, another new user is counted. For example, the same person engaging with your content on a phone and a tablet logs two sessions and is, therefore, counted as two users in most analytics solutions.
User-ID can associate multiple sessions (and any activity within those sessions) with a unique ID. When you send an unique ID and any related engagement data to Analytics, all activity is attributed to one user in your reports.
Because every unique user ID is considered to be a unique user in your Analytics reports, you get more accurate user data that better reflects the real world.
Analyze the signed-in user experience
You can implement User-ID in conjunction with your authentication system, so the unique ID that is used to identify a user account is sent to Analytics as the User ID. Any activity that happens when an account is signed-in can all be associated with that ID.
Because signed-in users usually engage with your content very differently than users that don’t sign in, the User ID lets you segment this subset of your traffic in your Analytics reports.
Access special tools and reports in your Analytics account
When you set up User-ID, you can access User-ID reporting views and the Cross Device reports.
A User-ID view is a special reporting view that only displays data from sessions in which a User ID and related data is sent to Analytics. With this view, you can get a better understanding of how this segment of traffic behaves differently than other traffic.
User-ID views include a set of Cross Device reports, which aren’t available in other reporting views. These reports give you the tools and metrics you need to analyze how users engage with your content on different devices over the course of multiple sessions.
If you set up User-ID in conjunction with your authentication system, User-ID views and Cross Device reports can help you get a better understanding of your signed-in users.
Find relationships between your acquisitions, engagement, and conversions
With data collected through User-ID, you can find and evaluate relationships between devices and engagement activities across multiple sessions, so you can better attribute acquisitions to conversions and see what your users do between these critical action points. You can use this data to develop new kinds of marketing campaigns and user experiences that are tailored to different device and engagement combinations.
Any user IDs you provide may be used to establish cross-device and/or cross-platform criteria, including for ads personalization. You can use this capability for powerful cross-platform use cases such as engaging uniquely with users who have yet to purchase on your app but who have already purchased on your website.
When configuring audiences you can configure criteria that allow for, or directly require, cross-device or cross-platform behavior. By default, all audiences are able to be cross device and cross platform, however you can specify device or platform criteria for control over that if needed.
Note that you can disable ads personalization at any time by marking events as NPA.