I’m not sure where you got the idea that the premium service included promotion. Last I looked, the subscription simply unlocked some specific features. If you just paid for it and hoped that meant your band was going to be promoted, you threw your money away, but that hardly seems like bandcamp’s fault.
He's thinking of engagement and discovery like youtube or the old MySpace experience for independent music creators. People land on the page and discover new artists and easy discovery of new ones.
