Decentralized Finance (DeFi) is considered a new vision of banking and financial services based on Peer-to-Peer technology, and in particular on the blockchain technology. Since 2020, DeFi has started to develop in the cryptocurrency markets. Then, with the increase in popularity of digital platforms such as Twitter, Facebook and Instagram, and with the launch of the Metaverse, DeFi has been introduced into the Social environment by the combination of social networking and finance in the blockchain. This new shape of DeFi has been called Social Finance (SocialFi). SocialFi can be seen as the social influence on any medium that can be tokenized, allowing to get monetary benefits from being part of SocialFi platforms. In detail, SocialFi has a special feature that is decentralized, open and user-controlled, and it started to be adopted by the communities. The main component of SocialFi is the Social token used to reward people. In this paper, we describe in detail the concept of SocialFi, and we discuss its application on future Social Media platforms.