The problem with channels a la carte is if you have two competitors, one of whom bundles content and the other of whom competes a la carte, there is a strong tendency for them to get into a ruinous price war.
Since people already do bundle, that makes getting into an a la carte variation very dangerous.
Since people already do bundle, that makes getting into an a la carte variation very dangerous.
See http://www.dtc.umn.edu/~odlyzko/doc/price.war.ps for details.