The prize, in the national reporting category, was awarded to veteran reporter David Wood. His 10-part series, “Beyond the Battlefield,” explored the lives of several veterans who were severely injured while serving in Afghanistan and Iraq.

The award may be Wood’s, but Huffington Post cofounder Arianna Huffington is a clear beneficiary. Over the past few years, Huffington has made a point of hiring experienced, well-known and (no doubt) expensive reporters like Wood.

The hirings are part of an effort to position the Huffington Post as a serious news organization — not, as former New York Times executive editor Bill Keller has described it, as an “overaggregator” of “celebrity gossip, adorable kitten videos, posts from unpaid bloggers and news reports from other publications… [with] a left-wing soundtrack.”

The Pulitzer is one small testament to the success of that strategy, and will likely feature prominently in the media kits the Huffington Post‘s sales team sends to potential advertisers.

The Huffington Post is the second online-only news organization to win a Pulitzer, following ProPublica‘s wins in 2010 and 2011. ProPublica partners with many offline publications, however, and focuses on long-form investigations rather than daily news.

Politico, which started as an online-only news organization and has since begun printing a print edition, also won an award this year in the editorial cartooning category.

Jeff Donn of the Associated Press and Jessica Silver-Greenberg of The Wall Street Journal were named runners-up for the national reporting prize.

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More than a week after KONY 2012: Part II – Beyond Famous hit YouTube, the video, which was also created by Invisible Children, has racked up about 1.7 million views. That’s less than 2% of the traffic that KONY 2012 got in its first five days. Part II’s performance shows that the success of the initial video will be hard, if not impossible, to repeat.

“The first campaign was an anomaly,” says Matt Fiorentino, director of marketing at Visible Measures, a video measurement firm. “We’ve never seen anything like it before.” Fiorentino adds that 1.7 million views is still very good for a video, particularly one with a social good message. “Compared to a regular campaign, it’s pretty good,” he says. “Whatever they put out is going to be very visible.”

Both KONY 2012 and its successor were designed to raise awareness about Joseph Kony, a Ugandan warlord behind the Lord’s Resistance Army, a guerrilla force dedicated to overthrowing the Ugandan government. The videos aim to have Kony arrested for war crimes by the end of 2012. Invisible Children is also planning a worldwide rally on April 20 called “Cover the Night.”

Released on March 5, KONY 2012 is now up to around 180 million views, according to Visible Measures. The success has drawn critics, including a group called Visible Children that took issue with Invisible Children’s overhead costs.

Invisible Children also drew unwanted attention a couple of weeks after the video hit when the group’s director and co-founder, Jason Russell, was detained by police in San Diego for charges of public drunkenness and lewd behavior.

With all that back story, there was a lot of curiosity about the KONY 2012 sequel, but Fiorentino says there was probably nothing Invisible Children could have done to garner another video with comparable views, except maybe to wait longer before it released the sequel. Says Fiorentino: “They needed to give the audience time to breathe.”

Representatives from Invisible Children could not be reached for comment.

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The three-year-old startup confirmed the 20 million number through a 4sqDay badge, which is being awarded to anyone who uses the app to check in on Monday (April 16 or “four, squared”).

“Thanks to all 20 million of you for making us part of your lives,” the badge’s message reads.

New user growth has slowed since the last time Foursquare announced a milestone. When the company announced it had reached 15 million users last December, it had tripled its userbase and added 10 million users in about one year.

Foursquare users have, however, checked in 2 billion times in the last two years, according to the 4sqDay badge message. On average, that’s 100 times each — suggesting that while checking in may be the least prevalent smartphone activity, those who do use Foursquare do so frequently.

A December 2011 study from Forrester Research found that just 5% of U.S. adults use any location-based check-in services, suggesting that checking in has a long way to go before reaching the mainstream.

But Foursquare’s user base is large and valuable enough enough to have attracted partnerships with big brands such as American Express, and its newest features emphasize its value as a resource rather than a check-in service. Its new web interface, for instance, focuses on discovery features, and the web version of its recommendation feature Explore now includes 250,000 restaurant menus.

Do you use Foursquare? Tell us why or why not in the comments.

More About: foursquare, location-based networking

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