Some folks keep asking why more artists aren't breaking into the mainstream through file sharing. This article suggests that they are--but that the record labels are taking all the credit:
"Record-label executives discreetly use Garland's research firm, BigChampagne, and other services to track which songs are traded online and help pick which new singles to release. They increasingly use such file-sharing data to persuade radio stations and MTV to give new songs a spin or boost airplay for those that are popular with downloaders.
Some labels even monitor what people do with their music after they download it to better structure deals with licensed downloading services. The ultimate goal is what it always has been in the record business: Sell more music."