When Mark Zuckerberg launched Facebook in his cramped Harvard dorm room in 2004, it was just one of the college sophomore's many online social experiments.
An earlier one, called Course Match, helped Harvard undergraduates see the courses their classmates were taking. Yet another, FaceMash, which gave Zuckerberg one of his first tastes of controversy, let students vote for the hottest kids on campus.
A talented programmer sometimes willing to dodge rules for information, Zuckerberg, 26, marshaled several of his projects to some level of success. But with Facebook, he hit it out of the park.
From a three-man operation fueled by Red Bull and beer, Facebook has grown into the world's largest social network. The company is on the verge of surpassing 500 million members and employs more than 1,400 people.
But though the story of Facebook, and the improbable adolescent who founded it, is impressive, it isn't without its complications. A rebellious, young CEO, mountains of personal information and an unbending vision to make the world more open can mean a bumpy path to success.
In his book, "The Facebook Effect," which is released today, technology journalist David Kirkpatrick chronicled the story of Facebook, from its creation to its controversies to its power to connect the world.
He is a longtime senior technology editor for Fortune magazine who interviewed Zuckerberg for the first time just as Facebook was taking off.
Kirkpatrick spoke with ABCNews.com Friday about Facebook, its privacy issues, its impact and its CEO. Below is an edited version of the conversation.
Author: Zuckerberg Started Facebook as a Lark
Why did you think that now was the time to write a book on Facebook?
"[It has an] impact on a variety of arenas of human activity, politics, marketing, media, our sense of our own identity, to some extent, personal behavior. What's really incredible to me is that Facebook, which is really, in many ways, a fundamentally new form of human communication, has been adopted now by 500 million people and is rapidly growing probably toward a billion and maybe beyond.
"And when you have such a huge proportion of humanity, and such a large percentage of people in our own country, and many other countries, using a new means of communication that has all these very powerful aspects to it, I think it's just really an exiting thing to write about."
Zuckerberg was 19 years old when launched Facebook, now he's 26 years old. Obviously, times change. How much has Zuckerberg changed since 2004?
"At his talk at [the All Things Digital conference last week], if you saw the videos he was really painfully recalling or having to fend off questions of when he was a 19-year-old college student. I think he started Facebook as just a kind of lark really, because he could, because he was a brilliant programmer and he had a good idea and he kind of thought it might be fun for his friends and he treated it very casually at the time.
"As he's gained more and more employees, he's reached [about] 1,500 of them, his own sense of responsibility has grown and there's no question he's not the same person he was when he was 19. ...
"Hopefully, we've grown some between 19 and 26 and I think he has in all the normal ways, except he's done it very much in public with an extraordinary, growing set of responsibilities. I think, in general, he's done a pretty good job of growing into his responsibility."
Zuckerberg: There Are 'Misperceptions' About Facebook
As he has taken on more responsibility and grown as a person and leader, what hasn't changed about him?
"I do think there are some key things that haven't changed, and that's the scope of his vision, really. That's one of the things that's really amazing about the story of Facebook. Even though he did start it as a lark, the ideas that he stumbled upon and the scope of the vision he had when he began was kind of truly monumental and vast and visionary.
"And I think he still pretty much holds to the same beliefs about how the world's changing and how services like this can make the world a better place, in his opinion. And how, really, the world needs and was inevitably going to get a new form of more social communication."
At the press conference Facebook held a few weeks ago to respond to privacy concerns, Zuckerberg said there were "misperceptions" about Facebook's (and his) approach to privacy. What do you think is being misperceived?
"The one thing that he emphasized [that day] … is when he says he's not doing this for the money, he's not kidding. And that's really hard for the press to acknowledge."
Kirkpatrick: Zuckerberg Not Trying to 'Milk It'
"It's a company, it's got 1,400 employees, it's got to make payroll and it's probably going to have over $1 billion in revenue this year. It seems incongruous that he should say he's not doing it for the money. But the thing about him that's weird is that he knows that he needs money to do what he's doing to change the world -- and that's the way he thinks of it -- but he's not really trying to milk it [or] make it into a phenomenal business now, because he basically views it as a very long-term project.
"|In that discussion], he says the biggest single disconnect, between how we're perceived on the outside and how we perceive ourselves, is that people think we're always changing the product in order to advantage the advertisers and make more money.
"One of the reasons I felt myself drawn to the whole Facebook vision is because it is a very charmingly non-commercial vision. [It's ] endearingly and [to a ] really unusual degree non-commercial for someone who is doing something very commercial.
"That's sort of where the press just doesn't get it because they just refuse to accept that could be possible and it's hard to blame the press for not understanding or accepting or understanding."
Zuckerberg Believes Information-Sharing Will Change
Is Zuckerberg interested in going public in the near future?
"No, in fact, Zuckerberg said that at [the All Things Digital conference] and it was one of the many things that people found hard to swallow. He would prefer to avoid taking the company public indefinitely, I'm quite certain.
"Because, especially, if you think about how he's going to have to navigate these very complex issues between public infrastructure and operating a company. It's going to be a lot easier for him to navigate these very difficult changes if the company is not public."
Privacy has dogged Facebook throughout its growth. Most recently, it faced criticism from government regulators over its privacy controls and Instant Personalization feature. How do you think Zuckerberg views privacy?
"It's important to look at this question of privacy with subtlety because it's a complicated thing and it's not treated very subtly by most of the coverage in my opinion. Honestly, I think it's wrong to say he doesn't believe in privacy."
Zuckerberg Pushes the Envelope on Openness
"But he believes that people ought to be able to control where their information goes. That's absolutely true. But he also believes that the world is rapidly changing in such a way that we're going to care less about where our information flows…
"And he also has found himself, by assuming that we're going to be less concerned about where information about ourselves flows, he has found himself constantly designing features that people turned out to like over the past few years.
"So he keeps pushing the envelope, assuming that the openness that people in his service have toward sharing their data is going to continue to grow very rapidly. And I think that he's pushed that too far on some occasions. …
"But, in reality, it's never really been the case, despite all the coverage, that you couldn't control your data on Facebook for the most part. The vast majority of your data has remained in your control."
Why Did Zuckerberg Want to Share the Story of Facebook?
In your acknowledgements, you thank Zuckerberg for being so supportive of your book. Why do you think he was so willing to make himself and his company available for this book?
"I think he was supportive of the book because he felt that Facebook did need to be explained … for better or for worse. And to my good fortune, he thought that I was capable of explaining it. And I really try to explain it in detail and subtly. ...
"When you grow as fast as Facebook has grown, I think he felt it was important to answer a lot of the questions that have been asked about the company.
"He isn't the world's greatest communicator in public settings, so Facebook actually doesn't have very many people internally who are extraordinary communicators. …
"It's amazing to me how wide he opened the kimono. Basically, everyone at Facebook talked to me. The only person they didn't want to let me talk to was Eduardo Saverin [an early Facebook co-founder], with whom they settled a lawsuit."
How do you feel about the story of Facebook now that the book is complete?
"I really do feel fortunate that I had the chance to write the book and I think it's important to really understand what has happened with Facebook, because it's just gotten so big so fast. I don't think any of us fully understand why that happened. I don't even think Mark Zuckerberg fully understands why it happened.
"There [are] certainly some huge elements of luck and just being at the right place at the right time."