According to Jeff Jarvis, defenders of self-exposure on the Internet need all the support they can get. “I have learned that the more we share, the more we benefit from what others share,” he writes in “Public Parts.” “I am a public man. My life is this open book.” Jarvis has built up a speaking and consulting career as a sparring partner for privacy advocates, who he believes “swarm,” “fret” and “worry” too much about the dangers of personal exposure online. Styling himself an advocate of “publicness,” he has attracted attention by blogging in graphic detail about his successful treatment for prostate cancer. Now, in his second book, he offers himself as a model for citizens across the globe, promising to demonstrate how sharing on the Internet is “a means for real people to connect with one another.”

For a so-called “open book,” Jarvis is surprisingly selective in the personal details he reveals. We learn that he was proud to go on the Howard Stern show and to talk about his malfunctioning private parts. He also liked taking naked saunas at the World Economic Forum at Davos, especially after a reader of his blog recognized him in the nude. A German friend explains that Europeans are comfortable being naked in anonymous saunas because “no one knows who you are,” but Jarvis draws the opposite lesson. After “living online,” he says, “I found it was, indeed, no big deal to be naked in front of men and women, even people I knew.”

There are many limits, however, to Jarvis’s willingness to lead a transparent life. He “won’t deny seeing porn” but refuses to share his browsing history. (“The problem is context: You may draw unwarranted conclusions about me that I’m not able to see and correct or explain,” he writes. That’s a concise definition of the value of privacy which Jarvis spends the rest of the book attacking.) He also refuses to disclose his total income and assets from teaching, blogging, writing and speaking. “Why? Even I’m not sure,” he says. “If I did, I’d be setting myself apart and people would wonder why.”In other words, he is happy to reveal personal details selectively when they serve his financial interests by creating an illusory bond with a faceless audience, but as soon as transparency threatens to embarrass him, he rediscovers the virtues of privacy.

It turns out that Jarvis is not an advocate of principled transparency at all, but merely an advocate for his own career. As a result, his personal revelations tell us nothing about what kind of person he really is. What does his wife think about his browsing Internet porn? How do his children feel about his vulgar descriptions of his private parts? In his acknowledgments, he thanks “my wonderful family” who “cope with the trials of living with a too-public husband and father,” but in the book itself we have no sense of what those trials actually are. Although he insists that “publicness builds relationships,” it’s hard not to wonder whether, in the case of his family, self-exposure has had the opposite effect. In the end, the generically prurient details that Jarvis blogs, tweets and broadcasts reveal nothing memorable or true about him as a husband or father: In his hunger to market himself to the crowd, he reduces himself to a slick abstraction.

There are moments of inadvertent insight in “Public Parts” where Jarvis seems to recognize the costs of personal exposure. Describing the film “We Live in Public,” in which the director wired his apartment with 32 video cameras and filmed his life, Jarvis notes that the director’s girlfriend, who allowed her audience to tell her how to behave during a fight, sacrificed “a little piece of her individuality.” By letting the public “make her decisions for her,” he notes, “she crowd sourced her life.” Jarvis, too, has crowd sourced his life, and the result is similarly flat, blurry and ultimately banal.

’Public Parts: How Sharing in the Digital Age Improves the Way We Work and Live’ by Jeff Jarvis (Simon & Schuster)

Jarvis’s subtitle promises that digital sharing will improve “the way we work and live,” but his real motive, as he confesses in his book, is more mundane. “Most of us secretly want to be famous, don’t we?” he asks plaintively. In another moment of candor, he confesses that writing books isn’t his ultimate goal; instead, he writes books to “build my public reputation” in the hopes this will “lead to other business.”

Although it may have ginned up his speaking fees, Jarvis’s book is slapdash in its reasoning as well as its prose, like a blog he couldn’t bother to edit. (“Publicness also needs its advocates. This book is one of them,” he writes awkwardly.) That’s not to say that “Public Parts” is devoid of insights. As a self-styled “Internet triumphalist,” Jarvis managed to interview a series of tech moguls, including Mark Zuckerberg of Facebook, although the wisdom that emerges doesn’t exactly break news. (“In the future, things should be tied to your identity, and they’ll be more valuable that way,” Zuckerberg confides.) Jarvis also has plenty of up-to-the-minute details about the latest social networking technologies.

But despite Jarvis’s suggestion that he deserves a medal for defending the social and commercial benefits of sharing on the Internet, those benefits are obvious to anyone with a smart phone. Jarvis’s distinctive contribution to the privacy debate is his eagerness to attract attention by any means, at no matter what cost to his own dignity. “I will admit to savoring the precious few moments of demicelebrity I’ve had,” he confesses. “Sorry I’m just being honest. I like the attention. I’m human.”

Jeffrey Rosen , a law professor at George Washington University, is an editor of “Constitution 3.0: Freedom and Technological Change.”


How Sharing in the Digital Age Improves the Way We Work and Live

By Jeff Jarvis

Simon & Schuster. 262 pp. $26.99