Jonah Peretti: And at number one on Buzzfeed's list is...

If the name Jonah Peretti rings even fewer bells than his website Buzzfeed, then you're probably over 35 or ailurophobic. Only old age or a pathological fear of cats could explain not knowing about one of the world's fastest-growing websites that's turned so-called listicles about furry animals into a phenomenon.

And you definitely can't have been listening to Radio 4 last week, when Peretti, 39, found himself "Buzzfeedsplaining the internet" to John Humphrys. The irony, I discover two days later, was that Peretti could have done with a bit of explaining himself: "I didn't really realise what a thing that programme was," he admits, in his quick-fire, classic American twang, after the interview caused Buzzfeed itself to go, well, viral.

As for the broadcasting institution that is Humphrys, well, "his thing" left Peretti nonplussed as well, though I'd bet good money on a Today programme listicle popping up in your Facebook feed or Twitter timeline; or, knowing Buzzfeed fans, probably both.

Buzzfeed's "thing" is lists. Lots and lots of lists. "We're obsessed by them," Peretti confesses, smiling. "If we take the same point and make it not a list, people don't like it as much."

Not that lists are anything new: witness the Ten Commandments (or, as The New Yorker would have it, "10 Judeo-Christian Moral Injunctions You Need in Your Life Right Now"). But Buzzfeed has taken list-writing to the next level, turning the genre into an art form. But be warned: they're addictive, which explains the hours I lost sidetracked while, ahem, researching Peretti.

Crucially, lists are easy to read on your phone, or "MO-bil" in Peretti-speak. And mobiles account for 50 per cent of Buzzfeed's traffic, which, as he told a packed conference room just before we met, means "content can't spread if it's not viewable on mobile". And "content spreading" is what Buzzfeed is all about: a whopping three-quarters of people clicking on one of its stories did so because one of their virtual friends shared a link on a social network. This has all sorts of implications for the future of media, which Peretti, a quintessential nerd genius, has been quick to exploit.

It all started with an email he sent Nike back in 2001, when the sports giant was offering customisable trainers. Peretti, then a postgrad at MIT media lab, tried to order a pair emblazoned with the word "sweatshop". The upshot – it was a No from Nike – was an email exchange he forwarded to a few friends, which ended up becoming an online hit. He figured he could be on to something big, given how easily "some anonymous grad student had reached millions of people without owning a printing press".

Initially, it was all about "intellectual curiosity": he wanted to try to understand why things go viral, which is "really a study of human psychology". Ten-ish years later, via a journey that has taken in co-founding The Huffington Post, Peretti says that others have woken up to the notion that "this might be the way people get their news and their entertainment, via sharing and media spreading through networks of people. This could become the dominant way for information to spread."

For what it's worth, Peretti, who pretty much headlined last week's Wired conference, is astonishingly humble about all this. There's none of the bravado you might expect from someone who is essentially a new media baron. Indeed, he bristles at the "pompous" term, while stressing that he doesn't mean to cause any offence to actual media barons. He skips neatly over any attempt to goad him into critiquing the newspapers that Buzzfeed, with its 85 million unique visitors in August, is poised to leave trailing in its wake.

We're sitting chatting in London's Tobacco Dock where Peretti, who lives pet-free in Brooklyn with his wife and twin boys aged four, has just finished his talk. Two pirate ship "skeletons" for children to play on are near by. I'm trying to avoid analogies with my own industry, but the ghosts of newspapers past hang heavy: we are just down the road from Murdoch's News UK.

"There's a difficult transition period with print being a less than ideal way to distribute news," is as far as Peretti will go. "We've had the advantage of starting fresh where we could build a model that made sense to us rather than adapt an old model, which is much harder."

So is Buzzfeed, which will follow its Brazilian launch last week with ones in Spain and France, and is keen to build on the start it has made here in the UK, the future of news? Actually, Peretti thinks not, noting "there'll never be one news source, the way that there's one search engine". The neat thing with Buzzfeed, he adds, is that it doesn't have to be "one neat package like a newspaper that drops on your doorstep". Its content might spread on Facebook, or on Twitter; hit a chord with old people, or young people; be more popular with Brits, or Yanks. All that matters is that someone is reading it.

This doesn't mean that the site's harder news stories – its editor-in-chief, the ex-Politico blogger Ben Smith, is a must-read for Washington policy wonks – have to clock up the same number of hits as pictures of basset hounds running. Thank the Lord. Peretti promises more investigative journalism, and is confident his site can earn the trust from its readers to do the requisite holding to account without which democracies falter.

But it is those cat pictures, or posts such as its genius 29-point guide to what makes a "Twitterstorm", that will bring in the serious traffic, he insists. If all this seems "trivial", to quote Humphrys, Peretti isn't into cynicism.

As a philosophy, that's served him pretty well so far.

Curriculum vitae

1 January 1974 Born to an Italian-American father, who worked as a criminal defence lawyer, and a Jewish mother, who was a teacher. Grew up in Oakland, California, with his younger sister, Chelsea (now a stand-up comic).

1996 Graduated from the University of California, Santa Cruz, with a degree in environmental studies. Started work teaching technology at a New Orleans prep school.

2001 While doing a postgrad at MIT, became an accidental viral sensation thanks to a caustic email exchange with Nike.

2005 Helped to set up The Huffington Post, with Kenneth Lehrer and Arianna Huffington. Set up Buzzfeed a year later as a "viral lab".

2011 Left The Huffington Post after it was bought by AOL to focus on Buzzfeed.

2012 Opened a Buzzfeed office in London.

And a list of buzzfeed lists...

* The 29 Stages of a Twitterstorm

* 13 Simple Steps to Get You Through a Rough Day

* 12 Reasons to Consider a Robot for Your Next Life Partner

* The 30 Most Important Cats of 2012

* The 21 Absolute Worst Things in the World