Traffic-counting metrics were at once impossibly complex and elegantly simple: If it’s moving, push it; if it’s not, change it or bury it. There were also surprises that the nimble HuffPost could leap upon, giving it wins over its competitors. On the afternoon that Heath Ledger died in 2008, for instance, the folks at HuffPost discovered that people were entering not his given first name as a search term, but the more familiar-sounding “Keith.” The name Keith was added to the tags, and all that Keith-generated traffic belonged to HuffPost.

Still, there was one caveat to the traffic hunt of which Berry was keenly aware: “The brand still mattered to us.” Which meant that there was a limit to the number of best-starlet-nipple slide shows the site could, or should, run. The blogs could not be HuffPost’s sole purveyor of depth. Nor could the business continue to grow if it was perceived to be yet another political site. Even as traffic climbed in 2007, there was a sense that HuffPost might face a dramatic drop after the presidential election, then still a year and a half away. Looking ahead, Peretti installed traffic-measurement widgets—and discovered that fully half of the site’s traffic came from non-political stories. So in the spring of 2007, HuffPost launched new verticals for media, business, entertainment, and, reflecting Arianna’s mission to spread the virtues of health and spirituality, Living Now.

The 2008 presidential election was indeed a bonanza for politics sites, HuffPost especially. Four years after the re-election of George W. Bush, a Democrat would be elected president and Huffington Post had almost doubled Drudge’s traffic, eclipsing The Wall Street Journal and Los Angeles Times. By September 2008, the site had become the traffic leader among its competitors, with 4.5 million monthly unique visitors—an increase of 474 percent over the previous September.

A few weeks after the election, Huffington Post announced that it had secured another $25 million in funding, this time from Oak Investment Partners, whose president, Fredric Harman, joined the HuffPost board. That brought total investment to $37 million, which had analysts estimating HuffPost’s worth at over $100 million. The money, announced the company’s new ceo, Eric Hippeau, would go toward acquisitions and hiring. Within a year, the company added local verticals in several American cities, launched the 23/6 comedy site—with its 2 million monthly uniques—and, perhaps most significant, entered into a news-sharing partnership with Facebook, to be called HuffPost Social News.

Yet there was still enduring criticism of the way HuffPost went about its work, especially from those whose stories were aggregated on HuffPost; over time, those pieces appeared at ever greater length on the site, diminishing the likelihood that readers would follow a link back to the source. Google News was, in comparison, a generous aggregator; it was essentially a headline and first-graph operation. Archrival Drudge consisted entirely of links back to the source. HuffPost, on the other hand, was far greedier about holding onto its readers. While it never stopped supplying links, it made them just a little harder to find. It seemed the sharing was to be one-sided.

No wonder there was gloating in media accounts of the 2010 demise of HuffPost’s self-congratulatory, yearlong foray into investigative reporting—one that Arianna had proclaimed was launched to “save” that honored, expensive, journalistic form. The Investigative Fund’s executive editor, Larry Roberts, whom HuffPost had snagged from The Washington Post, left after less than a year, and HuffPost’s attempts to have the enterprise incorporated as a nonprofit ran into a legal thicket, given that HuffPost itself was a decidedly for-profit venture that, as Gawker took great pleasure in pointing out, was the chief beneficiary of the dispatches the unit produced. The Investigative Unit, along with its funding, ended up being absorbed by its partner, the Center for Public Integrity.

And yet, despite the occasional misstep, the story of Huffington Post began to assume a relentless familiarity: month after month, year after year, the metrics moved in only one enviable, and northerly, direction. More and more verticals appeared—Style, Technology, Green, Sports, College, Books. HuffPost readers, comScore reported in 2008, were younger than those of Politico and Drudge. And when, in the fall of 2009, HuffPost’s 10 million monthly unique visits hurtled it past The Washington Post’s traffic, Hippeau took note, in an interview with

“We are now,” he said, “in the big leagues.”

Exclusive CJR interview: Arianna Huffington on what makes a good “gatherer.”

5. Voracious

A week shy of the first anniversary of their February 2011 union, Arianna Huffington and Tim Armstrong arrived at an already crowded television studio at AOL’s lower Manhattan offices for yet another display of their capacity to command attention.

Michael Shapiro is a contributing editor to CJR and teaches at Columbia's Graduate School of Journalism. His most recent book is Bottom of the Ninth: Branch Rickey, Casey Stengel, and the Daring Scheme to Save Baseball From Itself.