You can indeed say that - and people who demand artists work for "exposure" often do.

But there's no evidence it's factually correct.

And Bandcamp's model is based on selling tracks and albums with free previews, which is entirely different to free listening.

Right, and Bandcamp is probably the most pro-artist of the major music platforms, I would say. The project also benefits the artist but creating an infrastructure not controlled by Youtube or Soundcloud.

Source?