'Supergirl' scores big ratings – here's why

“Supergirl” took flight with ease on Oct. 26, scoring the best series premiere TV ratings for any show this fall.

CBS’s “Supergirl,” which stars Melissa Benoist as Superman’s cousin Kara Zor-El, became autumn’s highest-rated premiere for a new program. “Supergirl” was no doubt helped by the program that aired before it, CBS’s hit comedy “The Big Bang Theory,” which centers on scientists who love comic books, “Star Wars,” and other similar media. There would presumably be some overlap between the two shows' fan bases.

“Supergirl” also did well with younger viewers – the ratings for “Supergirl” in the valued 18-49 demographic was just slightly higher than those for the series premiere of the NBC series “Blindspot,” which was previously the highest-rated show among that demographic this year before “Supergirl” arrived on the scene. CBS has the highest median age for viewers among the four major networks and so is doubtless eager to bring some young viewers over to the network.

What accounts for the show’s success? Die-hard comic book fans no doubt heard the buzz about the show from this year’s Comic-Con, where the pilot was screened and got a great reception. CBS courted fans who were already anticipating a show called “Supergirl” and it paid off.

In addition, the marketing campaign for the show was extensive. Any casual fans who could be persuaded to tune in were most likely aware of the show.

The premiere date could also have paid off when it came to winning over regular viewers. Many of the new fall TV shows have premiered already – by comparison, NBC’s “Blindspot” debuted on Sept. 21, more than a month ago. By having the first episode debut after many other programs, “Supergirl” separated itself from the noise of other new fall programs. “Supergirl” wasn’t fighting for attention – it was a big event.

And of course, pop culture is loving superheroes right now, with Marvel movies topping the box office and almost every network and streaming service airing a superhero tale. In addition to the appeal of being a superhero story – all it would need for some viewers – “Supergirl” also separated itself from its superhero brethren by being one of the first stories, movie or TV-based, to center on a female superhero in some time. By debuting now, it just beat Netflix’s “Jessica Jones,” which will center on a female superhero as well and will debut next month.

In addition, the premiere of the show was well-reviewed, so viewers who were on the fence about whether to investigate the show may have been won over by reviews. Can the show sustain itself creatively?

Whether it can keep up the ratings also remains to be seen. ABC’s “Marvel’s Agents of S.H.I.E.L.D.” had great ratings at first but ratings have now declined, as have the ratings for Fox’s Batman series “Gotham.”