“I wanted a white building you could see out of,” Mr. Diller told The Observer by phone the other day. The man who created the Fox network twenty-one years ago and who was head of Paramount Pictures for a decade before that, was driving himself through Manhattan, on his way to a lunch appointment, and was stuck in traffic. “It was something of a contradiction in terms until Frank [Gehry] figured it out.”

Mr. Diller, whom Forbes magazine estimates is worth $1.5 billion, is a man who is used to getting what he wants. In early November, Mr. Diller, who is 65, announced a plan to spin off parts of his company to create five new entities: IAC, which includes several of Mr. Diller’s most well-known brands, including Evite, Match.com, Citysearch and CollegeHumor; HSN, home to several catalogs (Garnet Hill, Smith & Noble) as well as the Home Shopping Network and affiliated Web site; Ticketmaster; Interval International, a time-share resort holding company; and LendingTree, the online mortgage broker.

The spinoffs came after pressure from an increasingly impatient John Malone, the reclusive billionaire head of Liberty Media who owned 24 percent of IAC and had been agitating for changes in the months before the announcement.

“In a way, IAC is starting again,” Mr. Diller told investors on Nov. 5, the day the spinoffs were announced.

But it’s unclear whether the disparate Internet companies that make up the “new” IAC will, finally, bring the kind of success that Mr. Diller seems to crave—and that he had earlier in his career. He brushes off questions about his legacy at IAC, saying only, “I hope to leave it well.”

And so it’s hard not to see the building—and the companies he chose to keep under his aegis—as one more attempt to create a lasting media empire to rival that of his onetime boss, Rupert Murdoch, for whom he built Fox in 1986. The seeds of a bitter rivalry were planted in 1991, when Mr. Diller approached Mr. Murdoch and asked to be made a principal in News Corp. According to a 1993 New Yorker article, Mr. Murdoch’s response was, “There is only one principal in this company.”

Today, the specter of Mr. Murdoch hangs over the company; his decision to purchase Dow Jones, for $5 billion, is a life-defining gamble that Mr. Diller would be unlikely to make. IAC buys Internet companies on the cheap or develops them in-house with a lean staff, and attempts to turn them into profitable online brands. Mr. Diller’s career was once defined by his skill at developing original programming—this is the man, after all, who green-lighted The Simpsons, one of the most profitable television franchises in history. Now, his company is made up of sites like Pronto.com, which merges social networking with shopping, relying on strangers’ recommendations about consumer products; Gifts.com, which allows you to enter information about a gift recipient and then comes up with ideas; and Zwinky.com, a virtual-reality world geared toward ’tween girls. The paradigm has become, give the people a platform, and they will come.

The pre-split IAC had around 30,000 employees, spread out in offices around the world; the new headquarters currently holds 415 employees—like a special clubhouse for a select few. It’s in contrast to other iconic New York media headquarters, like the Hearst building or the New York Times building or the Condé Nast building, which house most of their companies’ employees. (Condé Nast CEO Si Newhouse has proposed building a new headquarters for his company on the Hudson rail yards site because he’d like to consolidate the remaining staffers who aren’t in the 4 Times Square headquarters under one roof.)

Anyone who spent time at an Internet company during the last or current booms will find the familiar totems at IAC: unlimited snacks and drinks on every floor, a Nintendo Wii in the cafeteria on the ninth floor, bagels all day. The bathrooms are a jarring departure from the generally muted tones: bright tiles in primary colors arranged in random patterns, and a bright yellow counter. It’s like an elementary school at the circus.

Open cubicles, each with a desk in a boomerang shape and individual coat closets, sit in the middle of each floor; offices line most of the walls. There are conference rooms tucked into oddly shaped spaces, tricked out with the latest in videoconferencing technology: huge flat-screen televisions, wireless keyboards, and SMART boards, which allow users on one side of the country to write something that—magically!—shows up on the other side. Then there are the chairs scattered around each floor, some of which have tables attached, as if to encourage employee interaction. (This reporter didn’t see anyone sitting in them in two visits.) There’s also a darkened “quiet room” with a massage chair, a couch and a flat-screen TV—and, of course, snacks. (But no gym! Perhaps they get their exercise in the long walk from the subway, or across the street at Chelsea Piers.)

At one point in his career, Mr. Diller was the consummate Hollywood player; then he revamped QVC from an office in the woods of West Chester, Pa., helping relaunch the career of his longtime best friend and wife since 2001, Diane von Furstenberg (The New York Times Vows column noted, “The marriage came after years of speculation about a relationship widely assumed to be platonic”) in the process.

By building his headquarters here, he’s staking the claim that IAC is a distinctly New York company, one that will—or, if it fails, will not—make an irrevocable mark on the city’s landscape, both mental and physical. “I think New York is the capital of the world, and I don’t know how much longer it’s going to be,” Mr. Diller said, when The Observer wondered why he chose to have IAC headquartered in Manhattan. “I feel that it’s where everything connects, particularly in the media business. And so I can’t imagine any other place where you would want to have a headquarters.”

But the building provides the somewhat paradoxical sensation of feeling both distinctly of New York and somehow divorced from it. The city—mostly the industrial remains of west Chelsea and various new condo constructions sites (and the spire of the Empire State Building)—is visible from three sides, with the Hudson River and New Jersey visible from the fourth. So New York permeates the building, but is not of the building. Inside, it’s all sleek and shiny and new, and quiet—it seems like the building has been plopped down, employees and all, straight from the eager-beaver land of Mountain View, Calif.

“We’ve always been not only willing but maybe even overanxious to not be tied to anything—meaning anything we’ve written,” said Mr. Diller. “We write nothing in stone. I mean, we’re not Valley Girls—we don’t change our opinion every hour and a half—but we’re willing to say we’ve gone in the wrong direction. We turn on a dime. We don’t look back, we don’t care, we’re very mistake-tolerant—as long as you don’t keep repeating the same mistake.”

But that’s a long-standing criticism of Mr. Diller—he’s great at the pivot, but not necessarily at admitting failure. The spinoff can be read also as a distraction from what some say is the fundamental weakness of the new IAC: a seemingly random hodgepodge of companies, united under the loose banner of “helping consumers,” and a business strategy that—because it’s so unencumbered, as Mr. Diller says—seems to change almost at whim. “The guiding principle overall is, we want to be in businesses where we can materially improve the lives of consumers using the Internet,” IAC president and COO Doug Lebda said in a phone conversation. “The common glue is that they all use the Internet.”

It seems like an oddly unfocused strategy for a multibillion-dollar company, and Wall Street has long been cool to IAC. Its share price is trading near its 52-week low, and has barely budged since 2005, when Mr. Diller spun off travel Web site Expedia. In August 2003, Business 2.0 ran a story speculating what the next technology mergers and deals would be; the magazine proposed that Yahoo would buy paid-search provider Overture and then merge with IAC. At the time, IAC’s market capitalization was about $22 billion—10 percent more than Yahoo’s—and so the magazine argued that “the odds would be on Diller winning control.” Today, Yahoo’s market cap is nearly $34 billion; IAC’s is just over $8 billion.

EVEN THOUGH MOST of the sites that will remain in the “new” IAC are reliant, in large part, on user-generated content, Mr. Diller still seems captivated by the idea of creating original content. On the 17th floor of an office building near Union Square are the offices of Connected Ventures, the IAC division made up of CollegeHumor, video-sharing site Vimeo, and Busted Tees, which makes jokey T-shirts (“Practice Safe Lunch: Use a Condiment”). IAC bought a majority stake in CollegeHumor in August 2006, in a deal reported to be in the $20 million to $50 million range, and kept its staff and culture largely intact.

CollegeHumor, by nearly any metric, is successful; the site generates around seven million unique users each month, and the content is almost insanely perfectly targeted to its core demographic: college students and those who want to be. Its videos, which are produced in-house, are generally funny, and the site has managed to maintain its good-natured, goofy-with-a-touch-of-sex attitude over the eight years it’s been in business. It’s a site perfectly attuned to an ultimately optimistic generation and socioeconomic bracket, one that managed to evade the last economic downturn and the war in Iraq, and revels in the shared nostalgia of having grown up concurrent with, or just ahead of, Michelle Tanner on Full House.

“Barry gets us,” said the site’s 26-year-old editor-in-chief, Ricky Van Veen, sitting in his glass-enclosed office in early November. Mr. Van Veen has floppy dark hair and was wearing a checked collared shirt under a V-neck sweater, and Converse sneakers. “He recognizes that he doesn’t know what a 19-year-old male from Kansas is into, and so he doesn’t pitch us ideas and stuff, but in terms of running an editorial media business—he gives us input,” said Mr. Van Veen. “I expected when we sold to IAC, we’d get calls or e-mails saying, ‘Take this down.’ But that hasn’t happened. I’m happy with that. I thought it was a trade-off to selling out.”

He continued: “It’s pretty crazy to have a business run by people who are 25 and 26 years old—a multimillion-dollar business. It’s not crazy for a start-up to be like that, but to have an entity of a public company run by 25- and 26-year-olds—that’s a little risky. They have a lot of trust.”

The new building may be a symbol of the new IAC, but it’s unlikely Connected Ventures will ever move in there. “Barry okayed us not going into the new building because he understood it wouldn’t mesh. There was a Heely craze at the time—literally half the office had Heelys,” said Mr. Van Veen, referring to the sneakers with built-in wheels that seemingly every child in the world was wearing at one time. “Talking to Barry, I think he realized he didn’t want Heelys scraping up those brand-new floors.”

But while CollegeHumor has maintained its momentum, some of the homegrown original content sites IAC has incubated are struggling. Last month saw the launch of comedy Web site 23/6, which had been in development since the summer of 2006 and was plagued by staff turnover pre-launch and differing visions of what the site would be. The concept seems to be a sort of Daily Show on the Web (the site’s newest editor, Jason Reich, is an eight-year Daily Show veteran who came on board in October), but so far the execution has fallen flat. “23/6 is very much a work in the very beginning,” said Mr. Diller, somewhat defensively, when asked how it was doing. “It doesn’t even have its walking legs.”

But what happens with 23/6 will be an important harbinger of things to come; it was repeatedly pitched to me as where the CollegeHumor audience would go when they outgrow CollegeHumor, but so far it seems that where the CollegeHumor audience goes when they outgrow CollegeHumor is, in fact, CollegeHumor. (Mr. Van Veen says his readers’ average age is now 28.) 23/6 is also not housed in the company’s shiny new headquarters; it has an office in SoHo, down the hall from the Huffington Post, with which it has a partnership, and from where it seems to be getting most of its traffic, thanks to outbound links on the site.

IAC’s other original content site is the e-mail newsletter Very Short List, which sends out one item—a DVD, a book, an online video—per day to a young NPR demographic. Started by Kurt Andersen and IAC’s head of original programming, Michael Jackson, and now overseen by a single manager and an editorial advisory board, VSL is a personal favorite of Mr. Diller’s. “No exaggeration, since VSL started [in September 2006], I’m sure I have ordered more than 30, probably less than 50, items,” Mr. Diller said. “Without VSL I would be much diminished.” But just as 23/6 is kind of an ersatz Onion or Daily Show, so VSL is kind of an ersatz Daily Candy for smarter people and a national audience. And though its earnest general manager, Gary Foodim, assured The Observer that plans are in the works for additional brand extensions (he declined to be more specific, though he hinted that the site might branch out into, say, specific e-mail lists for music lovers, film enthusiasts and the like), it remains to be seen whether VSL will ever be more than a quirky curator.

And so that gets to the question of influence, and whether Mr. Diller and Mr. Jackson will be able to create from scratch the type of online content phenomenon that will make the kind of cultural impact that it seems Mr. Diller still craves. “In terms of your target market, you want to be a part of their conversation,” Mr. Jackson told The Observer. And it’s that kind of measurement, the kind that is related yet also divorced from financial statements, that right now seems most elusive.