The typical pay-TV subscriber watches only 17 channels regularly, according to a Nielsen report from last year. That is a big reason why a new generation of viewers are finding online alternatives to avoid paying the average $74 a month it costs for cable. That basic bundle has expanded to more than 100 channels on average, according to SNL Kagan, and is required for consumers to then add on premium networks like HBO or Showtime or specialty services like NFL Network.