In these maps, you can see in which areas Comcast is the dominant provider before and after its monopolistic merger with Time Warner Cable:
It becomes pretty clear that cable companies in the United States have too much control of the market and not enough competition – This allows prices to stay high while quality stays low.
While the amount of time left dwindles before the greed catches up with cable companies like Comcast, here is an excellent analysis from John Oliver, who handily destroys the mob-like landscape:
http://bit.ly/1B6Ekog