You can't have everything be ad-based, in the end someone has to actually sell something to make money that pays for the ads. I always felt that this is a flaw in the ad-based model, you try to compensate for you own product not having any value by pushing other peoples products.

Anyway, if we're purely taking music, downloading it of TPB or listing to it on Spotify more or less makes the artist the same amount of money.

Software and books are different, because you can't really compensate for lose of sales with performances. Movies I'm unsure of, cinema could make the money needed to cover the prodution cost, but I don't know if that's viable.