Supporting a group still contributes to their success.
For me, personally I would never stan a nugu group that can’t chart well because they might as well just disband since they’re not making any money.
Supporting an already popular established group like BP or Loona will give you clout, something that supporting a group like NMixx and recently Twicewon’t give you.
Therefore there is nothing wrong with being a succes Stan. You’re boosting the popularity of a group by supporting them just for charting purposes. You’re buying the albums, streaming the songs, and going to concerts.
