Moreover, as compared with radio or print, there was on television a larger disparity in profit between the “winner” and “loser” of each time slot. Even the cheapest television programs cost far more to make than a radio show, meaning some ratings minimum was needed just to cover costs. The ratings winner, was able, moreover, to charge a premium for its advertising slots. This made the pressure to win even more intense, and also meant that content could not linger to evolve, as it might on radio or in a magazine—it had to pull in its audience or face cancellation.

Tim Wu, The Attention Merchants, loc. 490