TikTok doesn’t bump into the negative network effects of using a social graphs at scale because it doesn’t really have one. It is more of a pure interest graph, one derived from its short video content, and the beauty is its algorithm is so efficient that it its interest graph can be assembled without imposing much of a burden on the user at all. It is passive personalization, learning through consumption. Because the videos are so short, the volume of training data a user provides per unit of time is high. Because the videos are entertaining, this training process feels effortless, even enjoyable, for the user.
the reason tiktok has taken off is because it’s recommendation algorithm is really good, and it doesn’t need a social graph to thrive.