The upward trajectory of Killing Eve‘s ratings over its just-completed first season — nearly doubling its audience from the beginning to the end of the eight-episode season — is more than a little unusual. It’s unprecedented in the Peak TV era.

Most new shows today peak at their premieres, which is the point when the marketing oomph is at its noisiest, and then drift week by week as newer, shinier objects find the viewers’ attention. Occasionally, a show will find blips of modest growth over the course of a season, but they never ever ever do this:

According to BBC America’s research department, no show in the Peak TV era and going back for at least a decade has shown week-to-week gains in the key demos every single week over the course of a season. From the penultimate episode to the season finale last Sunday, the audience grew 26 percent. That audience is sure to grow even larger while the show is on hiatus, as Decider has exclusively learned that Killing Eve is headed to Hulu (and its 20 million subscribers) as its exclusive streaming home later this year.

BBC America president Sarah Barnett recently sat down with Decider to talk about what was so special about Killing Eve, how the network marketed the series so effectively in a highly fractured TV landscape, and what a critical role social-media engagement played in its week-to-week gains.

DECIDER: First, no spoilers. My wife and I haven’t finished watching the series yet.

SARAH BARNETT: It’s good co-viewing. Keep watching!

Had the show already run in the U.K.?

No, this was a BBC America commission. We greenlit it, and the BBC acquired the U.K. rights in a nice bidding war. It will air there later this year.

Start me at the beginning — several weeks before Killing Eve premiered — and tell me what indications you saw that the show had the makings of a hit.

I think there are two reasons why the show has seen unprecedented growth since the premiere. First, and the main reason, is that the show is so original and fresh. It subverts tropes in a way that audiences have found delightful, and it has extraordinary performances. I give a lot of the credit — most of the credit — to the show. It has to be exceptional to break out in this media environment today.

Second, I think the team at BBC America did some smart things. We knew we had a great show on our hands from the anecdotal responses of people who had seen it — my bosses, people in the industry, people at the network — and really responded well to the show. That made us approach the launch in a particular way. Our target audience probably wasn’t coming to BBC America in the numbers we would have liked, so we needed a marketing campaign to go find that target audience, which in this case was largely female.

We also struck up a number of partnerships with digital platforms like Betches and Refinery29.

How did you think about where to partner on digital. Were you looking mostly at female-skewing sites?

Our thinking was to be everywhere that our target audience is, and we tried to obsessively acquire that audience by being on a number of female-focused digital platforms leading up to the launch. We gave the first episode to those partners for free to make available for viewers to watch without having to authenticate through a cable provider.

We focused on a number of sites and not even primarily entertainment-focused sites for paid and unpaid partnerships and for advertising, and we did some advertising on TV. We knew the data analytics of who visited those platforms, and we structured a weeklong campaign where we hoped the target viewer would find the show everywhere she turned. We wanted to mimic the obsessive behavior you see on the show.

And you got some advance features and critics’ reviews.

There were great features like the one in Apartment Therapy, and we certainly benefitted from the amazing critical response.

Getting a show reviewed at all is more difficult than it used to be because there are so many shows to cover. Did publicity have to do a lot of hand-selling to critics? Did having Sandra Oh on the series get it on critics’ radar?

We had several things working in our favor. BBC America as a platform that critics have generally tended to cover, and our shows have generally been well-received. And Killing Eve had some special things about it even before critics saw it — Sandra Oh, who they certainly knew, and creator Phoebe Waller-Bridge, who they certainly knew after Fleabag as someone with a distinct and original voice.

Did social media become a bigger factor after the premiere?

Yes. We had the philosophy on social platforms of being as obsessive about fans of the show as they were about Eve and Villanelle and as obsessive as those characters are on the show. We were on social platforms commenting on what fans of the show were saying. The fans of the show are super engaged, and there has been a conversation around women and gender and queer characters. I just read a thread from a smart fan talking about Asian representation and how unusual and refreshing she found Sandra Oh’s performance. That engagement grew and grew as the show went on.

Was the amount of marketing you did across AMC platforms — 30-second spots on AMC shows, promo mailers, putting the show on the AMC app — on par with what you had done on other originals, or did you do more on Killing Eve?

It was similar. We did a little more on WE tv, which is part of AMC Networks and has a very energetic, female audience. We did more on WE tv than we had done on our previous original, Dirk Gently’s Holistic Detective Agency, which was more of a genre show and more compatible with shows on AMC.

The show premiered to 669,000 viewers, and then you had pretty significant gains over the next three episodes. What do you attribute that to?

Good, old-fashioned word of mouth. The biggest jump was to Episode 4, and it just took a little critical mass to get there. The exact rhythm of it is a bit of a mystery to me, but it does sometimes take a few weeks for word of mouth to gain a certain weight.

Was there any big media event that would have driven the fourth episode? Somebody went on Ellen or got on a magazine cover?

It’s so hard to track those things forensically. Sometimes there’s a lag before something picks up, and sometimes there isn’t. I’m a big believer in our social-media team and the idea that our audience has an audience on social media. The people involved in the show did a lot of classic media appearances and not just bunched around the launch. With the big bump in Episode 4 and knowing that Episode 5 was going to be especially electric with Villanelle and Eve having their first proper meeting, we did a lot of messaging around binging the first four episodes and then watching a can’t-miss Episode 5 live.

Did you signal viewers to any particular social platforms or give any guidance for how to communicate about the show?

We put #KillingEve out as the social handle. We had that all over the place in the weeks leading up to the premiere, so we were pretty intentional about that. And then fans organically developed #MurderLadySunday, which pulled together Killing Eve, Westworld and Into the Badlands. We embraced that and encouraged that and echoed it back to fans. We started to see that spring up around Episode 3 or 4.

The biggest ratings jump between two episode was between Episodes 7 and 8, and it’s extremely unusual to have a big bump like that so late in a season. Do you attribute that to a large amount of binging before the finale?

I do. We had the highest numbers we’ve ever seen on the app and on VOD platforms before the finale, so people we’re doing a lot of binging to catch up before the finale. It takes an exceptional show to generate that kind of interest, and Phoebe Waller-Bridge and her team created that. There’s such an electricity with the show, and people wanted to watch it live.

I think the length of the order was a factor. I think a six- or eight-episode season has an urgency that a longer series just does not have.

That’s such a fascinating theory. My gut feeling is that we’re all reassured when a show isn’t too dense in the number of episodes and the length of episodes. One thing that helped encourage people to jump into the show was the fact that we had greenlit Season 2 before we launched it. People wonder these days whether a show will be worth their while, and knowing there will be a second season helps with that.

The show will continue on BBC America and AMC platforms for another couple of weeks, and then the show will eventually go to Hulu. Why is there usually such a long quiet period before shows go to SVOD platforms?

It has become something of a standard to have a holdback before a show goes to a streaming service. Killing Eve will go to Hulu sometime around the end of this year. We maintain a longish period before it goes to streaming because of the deep and valuable relationships we have with our satellite and cable partners.

And you keep the right to air it again occasionally on linear, so you’ll likely do a few marathons of the series later in the year.

Correct.

Are you approaching Season 2 of Killing Eve with the same plan — eight episodes, April launch, similar marketing campaign?

I think the launch will be quite different for Season 2. The show will have been on Hulu for a period of time finding a new audience, and we would be able to continue airing it on BBC America. It’s the kind of show where the buzz can keep going between seasons, so we’ll start next season with a lot of positive sentiment from critics and fans for the first season, so I think it will be a different kind of launch. I don’t know exactly what yet, but I think it would be different.

GoldDerby, one of the Emmy prediction sites, ranks Sandra Oh within striking distance of an Emmy nomination for Leading Actress, and BBC America has some experience in that category with Tatiana Maslany, who won two years ago for Orphan Black. Are you planning to focus your Emmy campaign around Sandra Oh?

She was on the cover of The Hollywood Reporter last week with Angela Bassett, Thandie Newton, Elisabeth Moss, Claire Foy and Maggie Gyllenhaal. That’s extraordinary company, and we had set that up with The Hollywood Reporter before we knew Killing Eve was going to get such an ecstatic response. We’ll have another couple of things around awards season. Sandra Oh’s performance anchors the series with subtlety and warmth, and she’s a skillful actress who makes it look easy.

They’ll both be in lead rather that Sandra Oh being in lead and Jodie Comer being in supporting?

They’re both in lead. Sandra Oh is very well-known, and Jodie Comer is an out-of-nowhere discovery from the U.K. Rather than try to game it, we wanted to give them both their place in the sun. It’s a two-hander of a show.

[Laughs.] It’s a symphony in five seconds. It goes from charming to creepy to bratty teenager to terrifying. It’s amazing.

What’s BBC America’s next big original this year?

We don’t have another show announced right now, but soon we’ll have the radical reboot of Doctor Who with Jodie Whittaker starring as the first female doctor. We think that’s going to be a whole new conversation around a 50-year-old franchise. That’s kind of a dream.

Scott Porch writes about the TV business for Decider, is a contributing writer for Playboy, and hosts a podcast about new digital content called Consumed with Scott Porch. You can follow him on Twitter @ScottPorch.

Where to stream Killing Eve