Subscription source

Studio groups new subscribers by the surface that produced them, so a channel can see whether the last month came from one video, from Shorts, from live streams, from posts or from the channel page. The report needs enough traffic in the chosen period to appear at all.

It answers a narrow question well: which video is doing the recruiting. It says nothing about what those subscribers watch afterwards, and a video that wins the subscription source table while barely holding attention deserves a second look in the audience reports.