This suggests that they are using the file-sharing as part of the discovery process – it might even be driving the additional spending. If they are resorting to file-sharing to find new music, then, almost certainly, the mainstream isn’t providing enough (or anything) that is of interest to them. Stopping file-sharing wont bring these people back to the majors – unless those majors sign & promote a wider variety of artists. It might stop them getting to independents – or slow them down, but it wouldn’t change their decision to reject most (or all) of the mainstream.