Custom User ID is a type of ID you can manually collect within your implementation for numerous purposes:
- Reconciliation: First, its main purpose is to be a reconciliation ID between your userbase and Batch's. This means that you don't have to store Batch's anonymous IDs on your side since we will link the Custom User ID to the corresponding profile on ours.
- Using APIs: As you're able to address Batch with your own type of IDs, Custom User IDs makes the use of Transactional API and Custom Audience API much easier. You also need these IDs in order to use the Custom Data API and send us raw user data.
- Userbase attribute: Custom User IDs works best if you set them at login and reset them at logout. This way you can track the 'login state' of your userbase and target them according to the native attribute: 'has Custom ID'.
- Multisend: Also if you're targeting Custom User IDs while using the Transactional API, you will be able to reach all the device of a user that would be logged in on all of them (smartphone, tablet etc.).
- Debugging: Finally, this ID also makes it easier for you to find an installation of one of your clients in the Settings > Debug section. From there, you can visualize native and custom data that have been already collected on a user.
Keep pushi-... collecting Custom User IDs!