Something To Consider

Simply put, networks generate revenue through advertisements. Cable networks, on the other hand, have the advantage of also collecting subscriber fees. Wonder why your cable bill is $150? Three dollars are going to ESPN, $1.50 to Comedy Central and so forth. Given this model, it's no wonder why networks have to rely heavily on reality programming and take a huge blow when the Grammys or Oscars fail to produce strong ratings (fortunately more people are watching TV this year than ever before).

This NYTimes article is worth a read