YouTube has updated the Analytics Subscriber report to make it easier for creators to understand where their subscribers come from. To do that, YouTube has added more categories in the report, that are available starting September 18, 2017, and moving forward. Unfortunately, older data will not display information in the new categories.
YouTube Watch page - Shows how many subscribers come from the subscribe button on individual video watch pages.
Subscriptions feed - Understand how the subs feed contributes to subscribes and unsubscribes.
Interactive features - Show how many subscribes you got from cards, end screens and annotations
For the full list of categories click here.
Why this matters
Understanding how users subscribe to your channel can help you measure the effectiveness of your channel overall, what works, which is where you should focus on, and what doesn't work, as you may be able to save time/work in areas that don't produce the results you want to achieve. This report is also helpful to know where your content is popular and what videos are increasing your subscriptions or unsubscribes.
How to check your subscriber report
In case you don't know how to see your Subscriber report, these are the steps you should take:
Note: Keep in mind that the number of subscribers in YouTube Analytics is delayed by approximately 48 hours.