Fair point, but I think my meaning did not come across correct. Most articles today can be substituted with lower-cost versions of the same articles (news/revi

Fair point, but I think my meaning did not come across correct. Most articles today can be substituted with lower-cost versions of the same articles (news/reviews are good examples of this). There's your fungibility. Regardless though, publishers still hold onto their content, because it's one thing that Twitter/Facebook is lacking.