While searching Red Herring's site for something, I stumbled on an article from April 2005 that I'd missed the first time which provides a good overview of the current state of on-demand music and video. It has two tables comparing the characteristics of some of the major players in the on-demand music and video space. Link: Red Herring. --Dennis
"As broadband penetration deepens, the convergence of transfer speed, file quality, content range, and portability will make on-demand services an easy sell for consumers. Add in assurances of security and control, and it should get easier to pry the goods from labels and studios. But in the meantime, the on-demand industry will suffer through its awkward adolescence of tiny margins, content negotiations, and black-market competitors."