‘Walking Dead’: Ratings secret rival networks don’t want you to know

Everyone knows AMC’s zombie drama “The Walking Dead� is a hit. What’s less talked-about is how the show has evidently discovered some kind of anti-aging miracle potion that allows it to defy typical TV ratings trends.

“Walking Dead� wrapped up the first part of its Season 4 on Sunday, with a mid-season finale that drew 12.1 million total viewers, according to Nielsen.

It’s the highest-rated series in the history of cable TV. And even if it aired on broadcast TV, “Walking Dead� would be TV’s top show in the key adults ages 18 to 49 demographic, with a 6.6 rating. Only NBC’s Sunday night NFL games yield a higher number.

What’s unusual is that “Walking Dead’s� audience really isn’t getting any older -- despite the fact that the show is in its fourth season, and that it’s harder than ever to get young people to watch scheduled TV.

Typically, shows that become hits attract their youngest viewers during the first few seasons. Then, as that audience ages a bit and viewers a few years younger seek out newer fare, the average age begins an inevitable climb toward the upper reaches of the demo.

PHOTOS: Behind the scenes of ‘The Walking Dead’

That’s not happening with “Walking Dead.� The AMC show has a median viewer age of 33.2 so far this season, according to numbers provided by New York ad firm Horizon Media on Wednesday. That is slightly younger than the average age during its premiere season in 2010 (33.8).

What’s that mean? Well, given that “Walking Dead’s� overall audience is more than twice as large now as it was then, millions of those new viewers must be coming from the pool of people over 18 but younger than 33. In other words, mainly twentysomethings. By TV standards, that’s very young indeed -- and exactly the hard-to-get audience everyone wants. Remember, we are in a world where ABC, CBS and NBC are struggling just to keep people in their 40s from fleeing.

Naturally, all this is music to the ears of advertisers, not to mention AMC executives.

But it’s a safe bet broadcast executives wouldn’t mind if you forgot these stats.

What do you think of “Walking Dead�?

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