For the uninitiated, Bandcamp is one of the few outlets for indie musicians to sell their tracks directly to fans. They usually take a 15% cut of all sales, but on #BandcampFriday, they forego their cut so artists get more profit (minus CC and Paypal fees), at no cost to the fans. It's a win-win for artists and fans, at the expense of company profits.

Bandcamp started doing this as an act of goodwill during the pandemic lockdowns, when musicians couldn't perform live.

https://www.makeuseof.com/what-is-bandcamp-friday/