NEW YORK — With "Sharknado" and a tight battle between NBC and CBS, the week's Nielsen ratings illustrated how that traditional measurement is becoming less of a clear picture of how people are consuming television.
Last week's debut of the campy "Sharknado 2: The Second One" sequel averaged 3.87 million viewers on the SyFy network, the Nielsen company said. That was good, although not great: Seven other programs on cable television alone had larger audiences last week.
But SyFy didn't air the movie just once. "Sharknado 2: The Second One" was on four times last week, seen by a total of 9.5 million people. The movie also inspired some 581,000 tweets last week, more than any other program on television, Nielsen said.
There were shark-infested skies on SyFy all week, since the network aired last year's original movie four times, too.
Meanwhile, Nielsen said NBC narrowly beat CBS to be the most-watched network last week. The three most popular programs on the air last week were all on NBC — two editions of "America's Got Talent" and Sunday's exhibition football game between the New York Giants and Buffalo Bills.
Wait a few days, however, and CBS is likely to claim the week's crown. That's because Nielsen's weekly rankings are based on who watches the programs live or within the next 24 hours, and reality shows and sports programming are most likely to be watched live.
Dramas, which dominate CBS' schedule, are more likely to be time-shifted. For example, the July 14 episode of CBS' "Under the Dome" was seen by 7.6 million people within the first 24 hours, and just under 12 million within seven days — a 57 percent increase due to people watching on their DVRs or on demand. That week's one episode of "America's Got Talent" saw only a 17 percent bump when the full week's viewership was taken into account.
Fox saw an historic low in the ratings last week. Its prime-time average of 2.3 million viewers was lower than any other week's average achieved by any of the four biggest broadcast networks in Nielsen's records, with the exception of a couple of weeks in 2012 when NBC aired the London Olympics. Fox aired few original programs last week except for "Master Chef" and "Hotel Hell."
NBC averaged 5.4 million viewers for the week in prime time. CBS had 5.3 million, ABC had 4.5 million, Univision had 3.2 million, Telemundo had 1.3 million and ION Television had 1.2 million.
Three networks were bunched at the top of the week's cable ratings. TNT averaged 2.099 million viewers in prime time, the Disney Channel had 2.097 million and USA had 2.093 million. Fox News Channel had 1.83 million and History 1.81 million.
NBC's "Nightly News" topped the evening newscasts with an average of 7.9 million viewers. ABC's "World News" was second with 7.3 million and the "CBS Evening News" had 5.8 million viewers.
For the week of July 28-Aug. 3, the top 10 shows, their networks and viewerships: "America's Got Talent" (Wednesday, 9 p.m.), NBC, 10.79 million; "America's Got Talent" (Tuesday), NBC, 10.64 million; NFL Exhibition Game: N.Y. Giants vs. Buffalo, NBC, 8.53 million; "NCIS," CBS, 8.44 million; "The Bachelorette: After the Rose," ABC, 8.16 million; "60 Minutes," CBS, 8.05 million; "The Bachelorette," ABC, 8 million; "NFL Pre-Game Show," NBC, 7.56 million; "The Big Bang Theory," CBS, 7.2 million; "Big Brother" (Sunday), CBS, 6.58 million.
ABC is owned by The Walt Disney Co. CBS is owned by CBS Corp. CW is a joint venture of Warner Bros. Entertainment and CBS Corp. Fox is owned by 21st Century Fox. NBC and Telemundo are owned by Comcast Corp. ION Television is owned by ION Media Networks.