Standard and Poor's Rating Services said music labels are looking for alternative ways to boost digital sales to offset physical format sales declines, but it is uncertain whether the proliferation of music without digital rights management (DRM) will help to boost overall digital sales until a viable competitor for Apple's iPod emerges. The ratings agency views subscription-based models as most suitable to capitalize on rising music usage on social networking sites and said subscription services could create revenue opportunities from next-generation in-home audio systems with networking components. (Thomson Financial News)