I just read a cool article by Kevin Kelly called "Better Than Free." He argues that the Internet is about making free copies of everything (books, pictures, music, movies, etc.). So how do we get people to pay for something that's free? By adding value, of course, and he discusses eight "generatives," things that can't be copied but have to be created. They include immediacy (I want it now), personalization (I want only the part that interests me), accessibility (I want someone else to take care of it and make it available when I need it), Interpretation (I'll pay someone to help me use the free service), etc.
He talks about "findability," thinking of aggregators like Amazon and Netflix that help people find "the good stuff." He points out that one of the original "aggregators," TV Guide, used to make more than the TV networks, simply by helping people find the best of stuff that was available for free. He also argues that publishers, film studios and music labels are aggregators.