Eliza Brooke explains how Upworthy grows like crazy by testing many headlines:

Upworthy is claiming growth rates significantly higher than comparable sites like Business Insider and The Huffington Post and reporting over 3 million subscribers as of May, following the success of its hugely popular “Wondtacular” video.

Last October, Upworthy raised a $4 million seed round from investors including Facebook’s Chris Hughes, Reddit’s Alexis Ohanian, and John Johnson of BuzzFeed.

Upworthy’s mission is to make substantive content go viral. The theory is that people do care about important stories — just as much, if not more, than cute, silly cats — and that it just needs better packaging.

Upworthy’s recipe for virality is part emotional and part marketing. The first test is subjective: is the curator, one of about 20 team members searching for content, crying by the end of the video?

The next part is pure metrics and marketing energy. With “Wondtacular,” the team tested 79 different headlines for two days, trying out 8 different made up words until they had one with the best chance of blowing up.

Then there’s distribution. Upworthy has worked hard to build its Facebook community (they have over 2 million likes at this point) so that their users would act as amplifiers. They’ve clearly done a good job of that so far.

Koechley said the ultimate goal of Upworthy is to take up the noble mission of a dying old media and ultimately change the kind of things people across the nation are thinking about:

“To drive attention to the things we think really matter, get people paying attention, and pull some attention away from the frivolous stuff.”

Sounds like their investments from the founders of Facebook, Reddit, and BuzzFeed helped.

Since Upworthy is interested in content that can spread by those three mechanisms.

Upworthy is fascinating because they take other peoples' content and TRY to make it viral.

By writing clever headlines.

More Upworthy metrics and also how they monetize:

Last time we checked in with it, Upworthy already had apretty crazy growth story. At the time, the startup, which specializes in making videos and graphics about social issues go viral, was celebrating 11 million unique visitors in the month of March.

Well, that number now looks like chicken feed.

One-year-old Upworthy has just released its stats for May showing that it hit 30 million unique visitors for the month. To put that in perspective, BuzzFeed, which publishes more than 370 pieces of content a day, gets about 50 million unique visitors a month. That number also puts Upworthy ahead of Hulu.com, NBC Sports, and Us Magazine, according to Quantcast.

The site’s massive growth is a result of Upworthy mastering the art of social sharing. Its writers produce as many as 25 alternative headlines for a single piece of shared content in order to strike on the one that is most likely to grab people’s attention on Facebook and other social media. Edward Kim, the CEO of social measurement company SimpleReach, says Upworthy is “the single most socially optimized site we’ve seen.” Upworthy’s content accounts for a fifth of all social actions that the company measures – and that takes into account 5,000 publishers.

Much of the company’s May success can be attributed to one runaway hit: the story of Zach Sobiech, a teenager who became a rock star just before dying from cancer. The video about Zach, which had already been posted to FoxNews.com and People.com, generated 15 million pageviews thanks to Upworthy’s efforts. It also attracted 1.2 million Facebook likes, and was shared more than 760,000 times. The Upworthy community helped raise $300,000 for Zach’s cancer-research charity and helped drive his single, “Clouds,” to number one on iTunes.

Meanwhile, Upworthy has started experimenting with more monetization. While the company has long taken referral fees from NGOs and charities to which it drives Web traffic, it is now dabbling in sponsored content. On Thursday, it pushed out its first sponsored post, a Skype ad about a Ugandan man who comes to America and uses Microsoft’s teleconferencing tech to stay in touch with his family.

The ad was posted under the tag “Ads we like.” Upworthy’s founders, Eli Pariser and Peter Koechley, say the site will only share ads that fit the brand’s ethos of lifting up content that “really matters.”

The company has also launched its first sponsored vertical, “Workonomics,” a series about work and the economy presented by the AFL-CIO. On its website, Upworthy says, “Sometimes, when we want to pursue more specific or nuanced subjects — areas where we may have to dig deeper to find media that really moves — we look for partners to underwrite our efforts.”

Pariser and Koechley say they’re only dipping their toes into this sponsored-content strategy right now and will be testing it out over the summer. In the meantime, the founders remain optimistic for the prospects of building a new media company, even as the walls of traditional media businesses crumble around them.

Upworthy’s first piece of sponsored content is pretty good, actually: