NEW YORK • Every day, Ellen Pao receives written messages of support from all over: to her office, through her lawyers, over e-mail, on LinkedIn, in postcards she keeps in a small wooden box on her desk.

"Thank you for paving the way for women to come forward," writes someone in Florida.

"I believe (Fox News anchor Bill) O'Reilly would still have a job except for steps taken by you and so many others," reads another message.

She has heard from Ms A. J. Vandermeyden, the former Tesla engineer who is suing for gender discrimination; Ms Susan Fowler, whose blog post about her time at Uber toppled its CEO; and Ms Niniane Wang, whose story of sexual harassment at the hands of a prominent investor led to his and a number of other resignations.

Pao, 47, was the junior venture capital partner and former interim chief executive of Reddit who, in 2012, filed a gender discrimination suit against her employer, the powerful venture firm Kleiner Perkins Caufield & Byers.

In a case that captivated Silicon Valley, she accused her bosses of not promoting her because of her gender and retaliating against her for complaining. She turned down a seven-figure settlement to testify in a jury trial, seeking US$16 million in lost wages and tens of millions in punitive damages.

She lost. But in the process, she gave many women in corporate America a crash course in gender discrimination (the subtle kind).

This month, she is releasing a book, Reset, chronicling the details of her lawsuit and its aftermath, which, she writes, "almost ended my career in tech, cost me half a million dollars and launched a thousand hit pieces on me and on my family".

It follows her time at Kleiner Perkins, from early days as chief of staff to Mr John Doerr, a partner; the tangled affair with a married colleague she said harassed and retaliated against her; to the trial and what happened after, including the Reddit stint and her time now as an evangelist for corporate diversity and the co-founder and CEO of a non-profit called Project Include.

It is also the story of what led her, the daughter of Chinese immigrants to New Jersey, to this particular place.

Pao is the middle of three girls, an introverted high achiever who got perfect scores on almost all her tests. Her mother, one of the first women to receive a PhD in computer science from the University of Pennsylvania, taught her to code: a skill Pao is now passing down to her daughter, who is in elementary school.

She majored in electrical engineering at Princeton, where her father, a mathematics professor, had received his doctorate and then got degrees in law and business from Harvard.

Pao today may speak of social justice, intersectional feminism, the difference between "equality" and "equity", and the moral responsibility she felt to speak up. But she was a belated activist.

In the book, she describes declining to join a sit-in at law school protesting professors' claims that African-Americans and women were not qualified to teach because she did not feel comfortable "taking a side publicly".

Then came her first job out of law school: the male partner who would brush up against female employees in the hallway, whom she tried to ignore; a female lawyer sent home for wearing pants; after-work trips to the strip club Scores.

"At the time, I tried not to think much about those incidents, hoping that just working hard and keeping my head down would help me push past and ignore them," she writes.

By her own account, Pao was a rule follower. She chose not to hire a publicist during the trial and willingly turned over hundreds of thousands of e-mails to the opposing counsel, which she now regrets. She goes to church on Sundays, does not drink and is extremely hesitant to talk about her personal life.

Believing in meritocracy, she thought she could power through any inequity by working twice as hard. "I had faith in the system," she writes. But she told of being excluded from meetings, undermined in front of clients and among a group of women not invited to a company ski trip and a dinner with former United States vice-president Al Gore because as a senior partner put it, they would "kill the buzz".

On another trip, she joined a group of senior staff at the front of a private jet, only to be subjected to talk about pornography and preferences in type of "girls".

In written evaluations and performance reviews, Pao was given high ratings yet she was passed over for a senior-level promotion. She was criticised both for being too passive, but also too pushy; for not speaking up enough, but also being too opinionated.

"Everything was conflicting: You talk too much/not enough. You're too data-oriented/you don't bring enough information," she said, sitting in the shade of a roof deck at the Kapor Center, a social-impact fund where she is an investor and head of inclusion and diversity. "There was no consistency and it was just baffling to me. How do I improve?"

Much of the behaviour she experienced was inappropriate. But could it be proven illegal in court? This was no overt pay discrimination or being barred from certain jobs because of her gender. This was harder to document, to explain and ultimately to prove, but, she argues, just as damaging.

"Taken all together, these seemingly minor moments, these 1,000 paper cuts, create an unwelcome, subtly hostile culture," she writes.

She sent a letter to her bosses outlining her complaints. They brought in a private investigator, who found no wrongdoing by the company. And so Pao sued, retaining the services of a lawyer who had won a US$7-million sexual harassment case against a powerful Silicon Valley law firm in the 1990s.

Public support was sparse at first.

At least one woman founder told Newsweek the case was "ridiculous" and that she hoped Pao did not "get a dime", while in The New York Times, David Kaplan, author of The Silicon Boys, was quoted saying he was "sceptical" of the claims.

But at the crux may have been the fact that her claims, to many women, almost seemed ordinary. The kind of stuff they put up with every day.

Ms Sarah Lacy, founder and editor-in-chief of the tech website Pando, remembered thinking at the time that if Pao had a case, then so did every woman in the US.

"I think ultimately the same thing that hurt her made women all look at their own lives very differently, and say, 'Okay, this is not acceptable. This should not be a part of doing business.'"

Pao may not be a natural leader. "It's not my personality," she said, recounting going to see Steve Jobs speak and watching him be swarmed by people afterwards. "I remember thinking, 'Oh my god, I don't ever want that job.'"

Yet, to a certain cohort, she has become one.

This year, she appeared on stage with law professor Anita Hill at a sold-out event in San Francisco. Uber CEO Travis Kalanick had not yet been fired, but he would be soon after; that week, the University of California, Berkeley had announced it would pay US$1.7 million (S$2.3 million) to a woman who accused its former law school dean of sexual harassment; and O'Reilly had been fired from Fox News.

The outcomes are different, but what founder after founder, lawyer after lawyer, academic after academic, keeps saying is the same: None of that would have been possible without Pao.

"I've been here since 1999," Ms Lacy said. "There is no one - man, woman, founder, VC (venture capitalist), the most aggressive feminist, no one - who would have thought a male VC would get fired for propositioning a woman. It's just a radical change."

NYTIMES