TikTok is the social phenomenon of the moment. According to Sensor Tower analysis, the app was already downloaded at least 1.5 billion times (data combined by analyzing Play Store and App Store). This year alone it has totaled 614 million downloads, finishing third in the general classification: behind WhatsApp and Facebook Messenger, and even in front of Facebook and Instagram (fourth and fifth respectively). It is true that the Facebook apps are already very mature, with billions of users and downloads, and therefore it is difficult to expect huge growths yet.
TikTok, a particularly popular social network among the very young, is widespread especially in China and India. This year the boom was in India: downloads in that region are 277.6 million, around 45% of the global total. China has made "only" 45.5 million downloads, but two things are true: the explosion was already there last year and Sensor Tower does not consider other Android app stores (the Play Store is found only at Hong Kong and Taiwan in mainland China is censored).
With numbers of these proportions, it is clear that the social (or rather Bytedance, the company that developed it) is trying to understand how to make money. For starters, it allowed content creators to insert links to the products used in their videos: at the moment it is only a test, but it will increase the loyalty to the platform of those who are successful with their videos. The demographic band in which TikTok is successful is fundamental for trade.