TikTok is going LIVE, with Twitch-like subscriptions | Mashable
This article describes how TikTok will be introducing a new feature in which people can pay a subscription fee to watch live streaming from creators and engage in online chats with the creators.
This is an example of how social media platforms features are used to increase people's use. Being a subscriber can give someone a feeling of being an "insider" with special privileges and being "in the know".
Also, if someone is not a subscriber they can experience feelings of missing out.