"Now there's a growing recognition among some record executives and performers that the people who are downloading illegally are frequently huge music fans and that marketing to them may be more desirable in the long run than suing or otherwise harassing them. By inserting promotional material into the decoy files, and then planting those files prominently on file-sharing sites, record labels and other marketers can turn what is now an antipiracy tool into an advertising medium.
Right now, only about 1% of the decoy files on peer-to-peer sites include promotions or ads, but the potential audience is huge."
-- WSJ, Oct. 18, 2006, "Record Labels Turn Piracy
Into a Marketing Opportunity" (in case you need to look it up after the subscription curtain falls)