????Marissa Mayer has been a pioneer in the unofficial "Geek is Chic" movement. Google's (GOOG) first female engineer, who is now the company's VP in charge of all things local, has appeared in Vogue, rocked the cover of Fortune's 40-Under-40 issue, and been nominated for Vanity Fair's 2011 International Best Dressed List. She is an angel investor in female-founded companies like Minted and One King's Lane. Mayer also mentors rising-star women through the Fortune/U.S. State Department international mentoring program -- and even has her mentees stay under her roof.

????Sometimes her extracurriculars drown out the recognition that Mayer, who is 36 and the youngest star ever on Fortune's Most Powerful Women list, knows precisely how to get ahead. Sure, she's been lucky. But she is also clever and strategic. On Tuesday, in a funny and candid interview at Fortune's Most Powerful Women dinner in Silicon Valley, Mayer explained how she does it.

Sometimes you just need to show up.

????Mayer found herself in an odd and maybe fateful situation when Tim and Nina Zagat, the famous restaurant raters, popped up at two conferences where she was speaking -- and sat before her in the front row. The first time they met, Tim walked up to Mayer, handed her his business card, and gruffly said, 'Welcome to local."

????Shortly after, in New York, the Zagats were in the audience again, front and center. And this time, Tim asked her to join his wine club.

????"I think that the Zagats are conference-stalking me," thought Mayer, who took control of the flirtation by asking Nina Zagat to lunch. Mayer was warned by Google M&A exec Neeraj Arora: "Don't say the acquisition word." But on the day they dined at New York's Jean-Georges (Nina's pricey suggestion) and continued their conversation at Zagat's Columbus Circle offices, Mayer couldn't help herself. She blurted: "Well, we're here to talk to you, maybe, possibly, about an… acquisition,"

????Actually, her directness worked. Google wanted to avoid a bidding war -- and the Zagats agreed to talk exclusively to Google over the months that they got to know each other. "There are times when you just have to show up," says Mayer, who learned this simple truth as the negotiations hit the final stage. Google left Zagat with a proposed deal on a Friday, to be finalized Monday. The talks could have taken place over the phone, but Mayer believed in-person was best. So she and her team did two red-eyes in four days. "Nina said, 'That was our litmus test,'" recalls Mayer. "They were like, 'Is this a good team to work with? How much of a personal connection do they want with us? If they come back, we want to be with [them].'"

????In September, Google acquired Zagat -- an ideal fit, Mayer believes, given Google's focus on local, mobile and social offerings.