A new study suggests that online music sharing could become a major force in marketing music. “Nearly one quarter of frequent online music users say that the ability to share music with others is a key factor when selecting an online music service. And a third were interested in technology that helps them discover and recommend music, such as tools that allow Internet users to publish and rank lists of their favorite songs. Perhaps most important for the recording industry, a tenth of those surveyed said they frequently make music purchases based on others’ recommendations.”