by Patricia Sellers

The most head-spinning thing about Arianna Huffington’s deal to sell the Huffington Post to AOL –besides the sweet $315 million price, which is 10 times HuffPo’s 2010 revenues and almost all in cash–is her expanded job description.

Once the acquisition closes, Huffington will oversee all of AOL’s media content including the recently purchased TechCrunch, Engadget, AOL Daily Finance, and MapQuest and Moviefone as well.

Her new purview–overseeing platforms that reached some 111 million unique visitors in January, vs. HuffPo’s 27.6 million–gives her an opportunity to wield an influence on a mass level that is, dare we say, Oprah-like?

“There is no other Oprah than Oprah,” Huffington said when I talked with her this morning. Comparing herself to the mass-market media queen, she added, “would make me sound like a megalomaniac.”

Even so, she admitted that her motivation to sell is, in part, to broaden her reach way beyond politics, where HuffPo began. Though the business started in 2005 as a political blog site, “only 15% of the content today is political,” Huffington, 60, noted. She sees AOL’s platforms as ideal places to propagate all sorts of non-political content–and specifically, to target women on various fronts. “One of my passions is women and health and how do we lead our lives better?” Huffington told me.

When I asked her what she will bring to the AOL properties, she replied, “The headline is reader engagement.” She is proud of the fact that HuffPo, through its generation of multitudinous reader comments and its partnerships with Facebook and Twitter, significantly beats AOL on the social networking front. Her mission, in part, will be to make AOL’s news and other content “fully social.”

Meanwhile, AOL CEO Tim Armstrong covets greater access to women and influentials (and by recruiting Arianna to his team, he captures both). Armstrong has talked for a while about an “80-80-80 focus.” His theory is that 80% of domestic consumer spending is done by women, that 80% of it is done locally, and that 80% of “considered purchases” are driven by influencers.

As for the influential and irrepressible Huffington, she is prepping for her new, busier life by moving to New York, while keeping her home in Los Angeles. “I’m canceling speeches and doubling down,” she said.

Last night, following the media swirl around the AOL-HuffPo announcement, Huffington flew from the East Coast to Los Angeles with Armstrong. Instead of sleeping, they talked and waged a one-on-one battle to whittle down to the fewest unread emails. “He was about to win, so I kept forwarding him emails,” Huffington confessed. She began the flight with 2,300 unread emails and got down to 750. That wasn’t good enough. Armstrong won the competition.