Supergirl comes along at a unique time in the modern era of superhero media - where it's now one of multiple comic book-based TV shows headlined by female superheroes (see also Jessica Jones), female protagonists (Agent Carter), and/or ensembles that include an even mix of men and women (Agents of S.H.I.E.L.D.). Best of all, each of these TV series are different, spanning genres that range from adult coming of age to neo-Noir and espionage thriller (both present-day and historical), so there's room for each of them to flourish.
Case in point: Supergirl has done well in terms of its ratings performance to date, and is certainly CBS' most successful freshman TV show for the 2015-2016 season. It thus doesn't come as a surprise that CBS has put in a full season order, ensuring that the story of Kara Danvers/Zor-El (Melissa Benoist) will continue on for at least twenty episodes.
CBS has formally picked up Supergirl for an additional seven episodes, having also given its other new Fall 2015 series (Life in Pieces, Limitless, and Code Black) similar additional episode orders. According to the network's press release, Supergirl currently averages 11.24 million viewers, with a 2.8/08 rating in adults 18-49 and 3.5/09 rating in adults 25-54. As a comparison, that's well above the ratings that were achieved by recent episodes of comic book series like The Flash and Agents of S.H.I.E.L.D. (3.34 million and 3.57 million, respectively).
Elsewhere, Jessica Jones star Krysten Ritter has given a shout-out to both Benoist and Supergirl as a series, via her Instagram account:
Had a second to get caught up on my non #jessicajones TV and wanted to give a special shout out to my girl @melissabenoist ! I've been a big fan of hers since she first landed in LA. I met her early on when I was casting a show that I was producing and it was clear even then, fresh off the boat, that she was poised to be a big star. I'm so proud and happy for her for landing a part that she totally shines in. Funny, strong, adorable, and radiant! Congrats fellow superhero lady! Much love!
Supergirl's numbers did drop following its premiere episode, but that was always expected - seeing as the pilot aired at a special time where The Big Bang Theory was its lead-in - and there is fair reason to think the TV series' viewer numbers will not erode too much over the remainder of its premiere season, heron out.
For one, the series was well-received critically from the get-go and word of mouth hasn't gone downhill since. Furthermore, the family-friendly program - as was co-created by Arrow/The Flash head honchos Greg Berlanti and Andrew Kreisberg, and Chuck alum Ali Adler - has the coveted four-quadrant appeal that allows it to pull in a wider range of viewers, in terms of demographics. Supergirl also benefits from having more of an episodic plot structure, compared to the far more serialized design of a TV series like Agents of S.H.I.E.L.D. - making it more accessible to newcomers, as a result.
That's not to say Supergirl doesn't have over-arching story threads - for example, the subplots that concern Hank Henshaw's (David Harewood) unknown allegiance and the dangers posed by Kara's aunt, Astra (Laura Benanti) - but as each week brings with it a fresh self-contained super villain threat (with Red Tornado and Jemma being next in line to battle Kara), that makes it easier for viewers to jump into the action without having seen any previous episodes. That approach will serve the series well, even as its mythology continues to expand over the multiple episodes that still lie ahead during season 1.
Supergirl continues tonight with "Red Faced" on CBS @ 8 p.m. EST.