One of the first times Sloane Crosley made a real friend outside of work after she moved to New York was at a party she threw for the 20th anniversary of Jay McInerney’s Bright Lights, Big City in 2004. Ms. Crosley was 26 at the time, and she’d been working as a publicist at Vintage Books since 2002. The party was at the Odeon, and Candace Bushnell was there giving out advice.

“The night had sort of whittled down to a table,” Ms. Crosley said over coffee at the Bouchon Bakery in the Time Warner building earlier this month. “It was [former Page Six scribe] Jared Paul Stern, Candace Bushnell, me, Elizabeth Spiers, [Grove/Atlantic president] Morgan Entrekin and a couple of other people at the end of the table who I think worked for Grove. And Candace Bushnell very sweetly started to give me and Elizabeth advice about, you know, work and life and all this stuff. It was actually very nice of her, but I’m not sure either of us really agreed with it. … A lot of it was about getting out of publishing, and how we were never really going to make money doing what we did.”

According to Ms. Spiers, who had recently taken a job as editor in chief of MediaBistro, Ms. Bushnell was talking to her and Ms. Crosley because they were the only ones still at the party who were under 40.

“She had Sloane by the shoulders,” Ms. Spiers recalled, “and she was saying, ‘You want a yacht, don’t you?!’ We exchanged e-mails about it the next day.”

Ms. Spiers, who is now a freelance writer finishing up a novel, is still one of Ms. Crosley’s closest friends. Among other things, this means that if the two of them find themselves at the same party, they might leave together afterward to get food. This is saying something, because when Ms. Crosley goes to a party, a lot of people want to leave with her afterward to get food. (Vegetarian food, that is.) As well groomed as she is well read—the first time we met she wore jeans and a delicate red shirt with frilly lace at the front not unlike what you might see on a very elegant pirate—Ms. Crosley is the most popular publicist in town, and as such, she is more universally admired than anyone who’s been working, dating and going to parties in this city for longer than a few months has any right to be. Against all odds, just about every book editor, magazine writer and media blogger in New York seems to think the world of Ms. Crosley—not an easy feat considering how much most of these people tend to snipe at each other.

“She’s a pretty damn genuine person,” said Curbed’s Lockhart Steele, who was a longtime managing editor of Gawker. “[Sloane is unique in this way] especially among media people. You deal with so much bullshit from people and so much bullshit from publicists trying to tell you this is great or this is the next great American novelist.” Ms. Crosley, by comparison, cuts to the chase with editors and writers, and conscientiously tailors her pitches to suit their tastes. In other words, where publicists of all kinds—for movies, books, socialites and dentists—have created a giant wall of noise, Ms. Crosley manages to be heard above the racket, recommending her writers and titles to others with a gentle caress instead of a swift kick.

Indeed, whether you’re talking to the effete musician Moby—who went on a couple of dates with Ms. Crosley some time ago and remains her friend—or the unequivocally manly Maxim editor (and former Page Six reporter) Chris Wilson—whom she counts, along with (current Page Six-er) Paula Froelich, among her inner circle—Ms. Crosley seems to inspire the same sort of tenderness and praise. Even Joan Didion confirms, “She is a very sweet girl.”

Call it a lazy comparison, but Ms. Crosley is kind of like that other Sloane, the beautiful, sly and assertive one played by Mia Sara in Ferris Bueller’s Day Off.

“I have really shiny hair. I think that might be it,” Ms. Crosley replied when asked why everyone is so crazy about her.

LATER, WHILE SITTING in a coffee shop in the West Village—inexplicably one of the only areas in Manhattan Ms. Crosley can comfortably navigate in spite of the spatial dysphasia disorder from which she has suffered since childhood—she politely said she did not find the question of her universal appeal very interesting.

Instead she wanted to talk about the book she has written, I Was Told There’d Be Cake, a collection of irreverent personal essays set in New York that will be published by Riverhead in April.

The book was born out of an e-mail Ms. Crosley sent to a group of friends during the winter of 2004. The e-mail was about how she’d tried to move from one apartment to another and managed to lock herself out of both—first the old one, then the new one—over the course of the day. Among the recipients of this e-mail was Ed Park, then an editor at The Village Voice. Mr. Park told Ms. Crosley that if she made it a little tighter and wrote an introduction, he could publish it in The Voice.

She did, and after the Voice piece came out, Ms. Crosley’s byline started appearing all over the place, including in the pages of The New York Observer. Her essays usually took the form of funny stories and observations—one was about how she was a bad vegetarian; another was about how goldfish were underappreciated as pets; others—see the one about how much she likes her big butt—bordered on provocative. Generally speaking they were light and aggressively quirky: Ms. Crosley came off as a nice girl who dared to be funny. Readers and editors around town responded, and pretty soon, she was maintaining two separate careers.

That Voice piece was by no means the first thing Ms. Crosley had written in her life—like a lot of book publicists, she says, she has wanted to be a writer all along. She grew up in White Plains, N.Y., and attended Connecticut College, where she majored in creative writing (and minored in Japanese and archaeology) and did summer internships at Mirabella and The New Yorker. When she graduated and moved to New York in 2000, she did so with the intention of finding a job at a magazine.

This proved impossible, though, and she decided to give book publishing a try after a friend who had taken the Radcliffe Publishing Course inspired her to find out what a “literary agent” did. She Googled it, and a Web site came up listing 90 agencies. Ms. Crosley sent her résumé to each one. Before long, she’d landed a job as an assistant at one of them, a psychotraumatic experience she would later turn into an essay for her collection called “The Ursula Cookie,” which peaks with poor young Sloane deliriously baking a Christmas cookie decorated to look like her boss’s face, in a misguided attempt to get on her good side.

When you ask Ms. Crosley what I Was Told There’d Be Cake is about, she happily says, “Disappointment.”

This is a weird answer, because Ms. Crosley seems pretty thrilled about the way things have turned out. More thrilled, it should be said, than most of the media people she’s friends with, many of whom seem to sulk from one Radar party to another feeling more or less disgusted with themselves and fatally suspicious of the people around them.

Indeed, Ms. Crosley appears actually to enjoy the clusterfuck: she has fun when she goes to parties, and when she finds herself in conversation with someone, she is not immediately consumed with anxiety about how she’s going to get out of it. This gives her grace, and people take notice.

Russell Perreault, Ms. Crosley’s boss at Vintage, calls her the perfect guest, and he has her up to his summer home in New Milford, Conn., as often as she’ll come. “It’s always fun with her,” Mr. Perreault said, “whether you’re playing badminton or tennis or you’re going on a hike.

“Obviously,” he continued, “as director of publicity, I get invited to a lot of parties. It’s part of my job. If I get a plus-one I always drag her along with me. If she doesn’t know everybody there, by the end of the party she probably will. She’s a great person to have on your arm, because by the end of the party you’ll know everybody, too.”

EARLIER THIS MONTH at the Housing Works Gin Mingle, an annual event held at the roomy SoHo bookstore that brings together all manner of editors and literary types, Ms. Crosley did not have to introduce herself too many times. When she decided to go outside for a cigarette, it took fully six minutes and six conversations before she managed to get from the back of the store to the front door.

Which is not to say she is a social butterfly of indiscriminate taste. Though she claims to like everybody “unless they do some damage” to her, she does worry that life in this city has made some of the characters she interacts with a little, well, soulless.

“The really scary thing about New York is not the fear that everyone is hiding their true self,” she said. “The really frightening thing is that they’re not—that that’s it. That they’ve become whatever person they’ve built up.”

Ms. Crosley calls this the “empty mask” syndrome, and as you watch her move about at a publishing party, you can see that for all the energy and enthusiasm she projects, she maintains a strict, quiet skepticism as she works the floor.

At Housing Works, everyone wanted to say hi to her: Older women—agents, editors, etc.—spoke to her with a conspiratorial sort of excitement; young men approached her one after another and behaved very transparently.

“She’s very charming, isn’t she?” one of them said, looking over with appreciation at Ms. Crosley. “She’s kind of irresistible.”

Earlier, an ex-boyfriend had walked by carrying something like four drinks; asked to describe Ms. Crosley, he gave a wistful smile before turning away. “Inscrutable!” he said to no one in particular as he disappeared into the crowd.

Most everyone else, including authors whose projects she’s promoted, said words like “funny” and “smart.” Which is fine—though you might expect something a little more vivid from people who get paid to make up sentences—because Ms. Crosley really is funny and smart. Her mind moves quickly, and she’s constantly making jokes—little ones, usually, that seem to come out of her mouth almost reflexively. Someone drops a credit card and she exclaims, “Man down!” You start saying something vaguely critical about her book and she says, “What if I just hit you?”, before bursting into nervous laughter. Half the times she coughs, she excuses herself and says, “Hairball!”

The author Jonathan Ames, who has worked with Ms. Crosley on a number of books, calls this “the humor of exasperation.”

These days, Ms. Crosley is a star at work, but the trouble is, she’s dealing almost exclusively with authors who make her feel unqualified to be writing a book. This might have been true anywhere, but it’s particularly bad at Vintage because it’s a paperback imprint, and most of the books its staff oversees come from Alfred A. Knopf, a house with a very sophisticated, very literary list. In effect, when Ms. Crosley isn’t promoting books by luminaries like Toni Morrison and Joan Didion, she’s working with people like Dave Eggers, Jim Shepard, Colson Whitehead and Jonathan Lethem. All of which gets her kind of nervous by the time she sits down on her couch at home on the Upper West Side to write one of her personal essays.

“You start feeling like, my God, have I not lived? What is it exactly that I’m writing about?” she says. “David Sedaris has Paris and Candace Bushnell has sex, and, you know, Chuck Klosterman has music. … What do I have?”

A big butt, maybe. And a hell of a lot of friends. Others have done with less.