When it comes to “Big Brother,” Peter Salmon has skin in the game as the chief creative officer of Endemol Shine, which makes and sells the format. But back when it hit British screens, in 2000, he was at the BBC, and the show aired on rival pubcaster Channel 4. It quickly overshadowed the Beeb’s own attempt at TV-meets-social-experiment, “Castaway,” an altogether more sober show.

“We saw ‘Big Brother’ and it just did it properly and was the human experiment we imagined we might have done ourselves. And like everyone else, we were transfixed,” Salmon says. “The fact you could watch it unfold it in front of your eyes was and is an abiding principle. I remember it well. Everything changed at that point.”

Produced by John de Mol’s Endemol (years before the company aligned with Shine), the show started out in the Netherlands in 1999, on RTL’s Veronica channel. Nine housemates moved into a purpose-built house, equipped with 24 cameras and cut off from contact with the outside world.

About 3,000 people applied via telephone to be on that first series. The format went on to become a global TV phenomenon. In an illustration of how the numbers swelled over the years, more than 200 million votes were cast for an eviction in the Brazilian version in March.

MTV had a similar reality show, “The Real World,” but “Big Brother” went global, and as audiences took to the show and it spawned a generation of reality hits, producers had to learn a new production language.

“It wrote the rule book,” Salmon says, “whether around participants and support for them [a bullying scandal in the U.K. was headline news in 2007], and changing technology as TV was becoming interactive. It was the start of digital and there were the first nibbles of social. This was the infancy of modern TV, and ‘Big Brother’ was the bouncing baby.”

A degree of flexibility in the format allowed it to be scaled up or down, and played out in different ways. Tonally, it is different from country to country. In the U.S., where Julie Chen Moonves remains the longest-serving host of the show anywhere, it is a frothy summer reality competition series. In Israel, it has been a forum for debate from both sides of the Arab-Israeli divide. The next iteration of the Finnish version will have ecological themes front and center.

“It banished stuffiness in TV…. there were fewer voices on TV and less diversity. When ‘Big Brother’ came along it demolished that”

“It is an envelope in which you can put societies’ dialog, challenges and ritual,” Salmon told Variety in an interview at Endemol Shine’s London headquarters. “Looking ahead in my own career or at what’s being invented in TV, I can’t think of anything that is emerging that will do anything but enhance ‘Big Brother.’”

For his firm, the continuing success of the show is crucial. A for-sale sign seemingly still hangs over Endemol Shine and a key question for suitors is whether there are enough gems in the catalog.

It was a blow when Britain’s Channel 5 pulled the plug on “Big Brother” in the U.K. last year, but Salmon says the format going off the air in some places – and returning in others – is part of the ebb and flow of managing a global format. It returned to screens in Poland and Finland in 2019. It will be back in Germany in 2020.

With surveillance and CCTV now omnipresent in many societies, creating a format anchored by the notion of an Orwellian all-seeing eye has either lost novelty value or become more relevant. Salmon believes it’s the latter. “It’s in line with how young people have grown up – they recognize in it and other formats like it the democratization of TV and the fact that media is manipulated,” he says. “They are very savvy. They know there is a producer or a hand affecting the things they see.”

Also in line with contemporary TV, the format has solid diversity credentials that stretch back to its beginnings. The first LGBTQ+ winner was in 2000 when bisexual Bianca Hagenbeek won the show in the Netherlands. In 2005 in the U.K., a transgender woman, Nadia Almada, won. Earlier this year, the Canadian version was praised for its representation of the first non-binary housemate, Kyra Shenker. In “Pinoy Big Brother” in the Philippines in 2006, popular matinee star BB Gandanghari came out as gay during the show and is now embracing their transgender identity.

As “Big Brother” moves from being reality TV’s precocious poster child to sometimes awkward teen, and edges into its 20s, Salmon reflects on the legacy of a show spanning 28,000 episodes over 471 series around the world.

“It banished stuffiness in TV,” he says. “I came through a more formal world where there were fewer voices on TV and less diversity. When ‘Big Brother’ came along, it demolished that. You can’t put that genie back in the bottle.”