I dont think this is likely the future but regardless its what some people are thinking
http://arstechnica.com/news.ars/post/20080505-report-ad-support-content-will-soon-dominate-digital-media.htmlAd-supported content is where it's at for the next five years, according to new survey results from Accenture. The market research firm surveyed 100 senior executives in the media and entertainment industry as part of its annual Global Media Content Survey in order to get a feel for how they believe digital content is evolving. The ad-based model is apparently more popular among media execs than subscription or even pay-per-view models.
62 percent of Accenture's survey respondents said that they saw content creators focusing on an ad-supported model by 2013. By comparison, 25 percent cited subscription-based models, and only 11 percent named pay-per-play services. Pay-per-download (like most video content offered through iTunes) did not seem to make an appearance in Accenture's survey results, either because the firm didn't ask or because no respondents chose it as a model they believe will dominate in the near future.
Not only will ad-supported content dominate the industry, execs believe that digital advertising will be bigger than traditional advertising within five years.
As I stated above I have serious reservations about this sort of hyperbole plan, I dont believe this model can work for all artists its likely only the more popular artists will enjoy the benefits of exposure, leaving those who cater for a minority left out in the cold, if this is the proposed future I dont think the music industry has one.