Sure, that's true, though if you allow streams on Bandcamp, those pay $0, so in terms of "try before you buy", any streaming service is better. It's only if you actually sell an album on band camp (or AmpWall, a smaller indie service that does a lot of the same stuff) that you'd get paid, as an artist.

I say this as a musician who has put out several albums both independently and with a label.