This is one of the arguments I've heard people who download music illegally use. The argument is that the speaker would only download the music because it is available to them for free. If it weren't free, they would have no interest in purchasing it. Thus, the artist would recieve no revenue whatsoever from that consumer, regardless of price.

Sherwyn is right. People think that they are downloading only one song, but if millions of people do it, then they are in fact denying the singers their money/royalties.