"Internet freedom is something I know you all care passionately about; I do too," wrote President Obama on Wednesday night during an impromptu question and answer session on popular link-sharing website Reddit. "We will fight hard to make sure that the internet remains the open forum for everybody."

"Sure thing," noted a user. "Do you like cats?"

In a moment, Reddit had explained itself to the millions of bemused web wonderers who surged to the site, many of whom had little idea of what Reddit is, and why the president of the United States had chosen to drop by.

Obama's visit is the high watermark of Reddit's steady – but recently dramatic – rise to become the "front page of the internet", where a voracious community of users submit links across a multitude of categories (subreddits) to be upvoted and downvoted. In December 2011, it served more than 2bn page views. The process is the web's simplest incarnation of the wisdom of crowds – the interesting stuff rises to the top, the rest sinks without trace.

But Reddit's "wisdom" is an intriguing one. A glance across the site at any time will find a wide-ranging buffet. As I write, in one corner, hundreds of Redditors are discussing a revolutionary mathematical model that MIT metallurgists are applying to metal alloys, while the World News subreddit is gripped by a debate over the implications of rises in the Chinese minimum wage. Elsewhere, a stunning image of some penguins congregating on an iceberg is narrowly outstripping a picture of a "sexy vampire" on the Reddit home page, where the most popular links from across the site jostle. The site's appearance requires patience – pages are chaotic and cramped, bursting with as many links as they can hold. Many fans (including myself) wail for a facelift, but the founders are wary of rocking the boat – a redesign of its once-biggest rival, Digg, was one of the main factors in its sudden fall from favour among the link-sharing masses.

Reddit's rapid oscillation from the cerebral to the inane is what makes the site so compelling. If you want to take the internet's temperature, a quick scroll down the Reddit homepage is usually a fair indication. The site was founded in 2005 by two 22-year-old University of Virginia graduates, Alexis Ohanian and Steve Huffman, and was acquired by Condé Nast a year later. The relationship between the publishing giants and the often puerile web community is a curious one – a recent leaked memo carried guidance from the upper realms of Condé Nast reminding Reddit employees that their genitals needed to be covered at all times within the office. Various parties scrambled to denounce it as a fake, but the scenario was entirely believable.

Among its most popular boards, the IAmA section (format: I am A politician/fireman/film star ... Ask Me Anything) is increasingly attracting big names eager to impress – or indulge – the Reddit crowd. Obama follows in the footsteps of Ron Paul, Larry King, Paul Krugman and, um, Molly Ringwald in entering the Reddit lion's den. Redditors don't always play nicely – Woody Harrelson was monstered for overflogging his latest film during his session, and the chat quickly descended into a barrage of questions over an alleged one-night stand he'd had with a student 10 years previously.

Somewhat predictably, Obama had done his homework, finishing his chat by referencing a comic meme spawned by a picture of him pulling a funny face in 2011. "By the way, if you want to know what I think about this whole reddit experience - NOT BAD!"

Reddit was never going to be a tricky wicket for the president. The site's users are overwhelmingly liberal, having famously catalysed campaigns to combat the Sopa (Stop Online Privacy Act), and mobilised thousands of people to attend an ironic "Restoring Truthiness" rally in Washington hosted by liberal TV hosts Stephen Colbert and Jon Stewart. Obama's campaign team would have been pleased to note the thread trending immediately below the president's on Wednesday night, pointing out that Mitt Romney's five biggest contributors were Goldman Sachs, JP Morgan, Morgan Stanley, Bank of America and Credit Suisse, while Obama's were the University of California, Microsoft, Google, DLA Piper and Harvard University.

By Thursday morning, Reddit had moved on, and the president's web chat was relegated to fifth place on its homepage, behind a picture of a man attempting to kill a moth by hoisting his cat to the ceiling, and a news story about a woman who went missing in Iceland before being discovered in her own search party. In a world of web curiosities, Obama is but one.

Benji Lanyado is the founder of RedditEdit.com, a new aggregator fuelled by Reddit.