Almost since its mainstream introduction in the 1940s and 1950s, television has been the dominant mass medium. Today, television ad revenues in the US are estimated to be between $60 and $70 billion. But the internet, like cable TV and DVRs before it, is shaking up the industry and fundamentally changing consumer behavior. There are what might be called "structural shifts" happening in viewing habits. The TV itself isn't going away but TV as we have known it may be.
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