Jeff Storan has an eye-opening article on the Simulmedia blog on our loyalty to TV, and lack thereof, at:
http://www.simulmedia.com/2009/05/segmenting-on-loyalty/

Here's the post:

Segmenting on Loyalty
Posted on May 11th, 2009 by Jeff Storan

In Simulmedia’s ongoing analysis of second-by-second television viewing data, we’re learning more about how people choose the programs they watch and how they watch the programs they choose. Some of the most surprising insights we’ve uncovered relate to people’s loyalty to programming.