Welcome to Step Two of our Getting Started with Amplitude Series. This series is intended to help you set up Amplitude in the quickest, most optimal way possible, by walking you through the Amplitude data structure and helping you identify the data your product should be sending to Amplitude. Specifically, we'll cover:
- Introduction & getting started
- Instrumentation pre-work: Things to consider before deciding what data to send
- Identifying your users: Requirements for properly tracking your product's unique users
- Event data: How to identify the events or user actions you should track
- User properties & event properties: The attributes you should send to upscale your analytics
- Cross platform instrumentation vs. separate platform instrumentation: The differences between them, and when you should choose one over the other
- Using the Amplitude platform: General tips and helpful definitions
(If you're a developer or product manager who will be responsible for instrumenting Amplitude, you should also read our getting started guide for developers.)
Amplitude uses a combination of three different methods to identify your users: device IDs, Amplitude ID, and user IDs. The first comes directly from your users' devices, while the second is an ID that Amplitude automatically creates once it has enough information to conclusively identify a unique user. The user ID, however, is something you'd set up.
In Amplitude, a user ID is a unique identifier applied to individual users. Using them is optional, but recommended: your product should set a user ID once a user has created an account, logged in, or is otherwise identified in your product.
Amplitude can use a user ID to reconcile events across multiple devices under the same user ID. Additionally, a user's event data will be merged on the backend so that all anonymous events prior to the assignment of a user ID will be connected to the correct user. For this reason, you can wait to assign user IDs if that makes sense for your product. Conversely, this is also why you should not set user IDs for anonymous users.
Once set, user IDs in Amplitude cannot be changed.
If your product doesn't currently assign user IDs, then feel free to skip this section.
Before continuing on to the next step, be sure to see this article about how Amplitude identifies unique users. It's got all the details you'll need.
Best practices for setting user IDs
- Don't set the user ID if there isn't one. For example, if you set the user ID to the string
Nonefor multiple users, Amplitude will not recognize those users as separate users. Instead, it will assume all those users are actually the same user, and it will group all events for those users together under that
Noneuser ID. As stated earlier, you can always set the user ID later.
- Don't assign a user ID that might change. User IDs are fixed forever, so don't, for example, set a user's email address as their user ID—email addresses change.
- User IDs are case-sensitive. If you set a user ID in a different case, Amplitude will track two separate profiles for the same user.
- Assigning user IDs server-side can be tricky. If you're running into issues assigning user IDs, please contact us.
When you're ready to move on, just click this link to go to the next step: Tracking events and understanding your users' actions.