It doesn't matter where she appears. It matters whether anyone looks at her.
The way to ban Coulter is not to buy her, not to listen to her, and to dismiss anything she says because she says it. If she were to say the sky is blue, I would ask for a photograph.
The media outlets need to know that people are actively not consuming their product when Coulter is featured. That will be enough, over time, to eliminate her appearances. "Banned by the media"? Nah. "Banned by the consumers" is the true poison pill.
She thrives on attention. Give her none and she will shrivel like the Wicked Witch of the West in the rain.