A social token is a direct way for an artist to communicate and represent value to their fans.
Typically when you want to support an artist you buy their merch, tickets to their show, or watch their videos.
Facilitating those goods and services for fans requires a lot of middlemen. You need manufacturing and distribution for merch, you need venues, security, transportation, etc for live shows.
A social token is just another product for their fans to consume. However, unlike the traditional methods listed above, the transaction is made and held directly between the fan and the artist. If I buy a social token from a person I like, I know they had a direct part in the creation and validation of that token, as opposed to a merchandising deal with a third party manufacturer set up by the artists business people.
Text Source: https://www.reddit.com/r/ethereum/comments/m64mae/what_is_a_social_token/