In addition to reading out the proclamation, Ms. Herman unveiled a Douglas Elliman Way street sign, which the brokerage has applied to the city to have installed on the corner outside their office, 57th and Madison. (The operation actually got its start about 10 blocks south.)

"I think he is one of the most important New Yorkers, because he basically created the real estate industry as we know it today," Ms. Herman told The Observer over champagne and cupcakes after the event.

All photos by Gotham Photo Company.

mchaban [at] observer.com | @MC_NYC

Yet just as man once thought the world was flat, times change, the impossible becomes reality, and we walk on the moon.

A similarly earth-shattering event has taken place, as Lenz has relinquished her crown, albeit in exchange for an even higher honor: the newly created Stratosphere Award, of which she is the sole recipient. Now, Lenz will no longer be competing for the top honors she has owned for the past eight years and will instead have to content herself simply with this new prize.

In a release, Herman, Douglas Elliman's CEO, called her best agent, and arguably the best in the world, "peerless." Lenz, meanwhile, took a moment to demonstrate her equally peerless wit: "It feels like they're retiring my number; but seriously, I see plenty of talent in this company and I think it's important that they be given the opportunity to achieve the ultimate recognition for their efforts. It is my every intention to help this pool of talent thrive in this very competitive field."

mchaban [at] observer.com | @mc_nyo

Manhattan brokers, who used to practically guffaw about New York’s beautifully, effortlessly, naturally rising luxury real estate prices, are conceding that gargantuan real estate bought during the boom will likely sell at gargantuan, maybe multimillion-dollar, losses.

What was once a freakish nightmare—only the masses take losses!—is now accepted with a matter-of-fact shrug: “Panic at the Plaza” was the headline in October on the Web site Curbed when the asking price for a unit bought for $14.94 million was lowered to $14.5 million. This month’s news that the apartment sold for $8.5 million, nearly half of what it had been bought for, didn’t make much of a ripple.

Last Friday, Aug. 7, alone, three sales deeds filed in city records showed big losses for big people at pristine addresses. Biggest was Steve Eisman, whom Michael Lewis portrayed in his iconic Portfolio cover story “The End of Wall Street” as “sort of a prick in a way, but he’s smart and honest and fearless.” The hedge fund manager made ingenious bets against subprime lending, but Manhattan real estate proved bigger than even him: His family’s sun-drenched, nine-room apartment at 1125 Park Avenue, bought in March 2008 for $6,995,000, sold this month for $5.2 million.

“After they bought it,” broker Michele Kleier explained this week, “they realized it was too small. They have three children, and they wanted to be able to give each child their own bedroom—and have a library.” As it’s laid out now, having a library means giving up a fourth bedroom. “It would have meant doing such a huge renovation that it would have taken such a long time, and it still wouldn’t have made sense.”

So Ms. Kleier put the apartment on the market in June 2008 for $7.5 million. The family could have gotten close to that price at the time, she said, but they couldn’t find an apartment they liked better, so they tried to stay put. “They really wanted badly to make it work.”

The co-op came off in July, but then on for $5,995,000 this April, when the market had already tumbled violently. “They’re very intelligent people. They’re very realistic people. They knew they were going to take a loss on it. We priced it to sell quickly, and they took the first offer they got.”

As these things go, Friday’s second deed was for a three-bedroom apartment at 2 Columbus Avenue that apparently belonged to Dennis M. Mathisen, a Minneapolis financier tied to BankFirst, which, after years of reportedly murky subprime lending, just became 2009’s 55th bank closed by regulators. A corporation in Mr. Mathisen’s name bought the condo for $3.05 million but sold it for $2.8 million.

"WELL, LOOK, ANYTIME YOU buy during a peak, if you have to sell within the next couple of years, you’re out of luck. That’s life. And I tell people there are choices in life, and managing expectations is key,” Elliman’s president and CEO, Dottie Herman, said Tuesday. “I didn’t make it the way it is. It is what it is, and sooner or later you have to stop being angry.”

Late last week, the 110 Central Park South penthouse that the philanthropist Iris Cantor bought in 2006 for about $15 million went to contract, after its price was cut to $11.9 million. “Everybody likes to make money,” her broker A. Larry Kaiser IV has said, “but you become realistic.”

“If they have to sell, for whatever reason, they’re going to have to take the nasty pill and swallow it,” said Barbara Fox, the head of an eponymous boutique brokerage. “This is not a time when we put our head under a blanket … shielding ourselves from reality. This is real life now.”

Friday’s third deed was for Bruce Lisman, Bear Stearns’ former co-head of global equities. Two years ago he put his four-bedroom apartment at 923 Fifth Avenue on the market for $22.5 million, which came down to $19.75 million, then $18.95 million, then $16.75 million. The place sold this month for $12.8 million, less than the $13,125,000 he spent on it.

One of his brokers, Mary Beth Flynn, said that the sale “turned out to be a break-even situation,” but she would not explain how he made up for the $325,000. “The apartment was a bit too big for him. It was just time to move on; he was very Zen about it, he really was, and still is.”

He’s not the only finance type suffering. Ramesh Singh, the former global head of mortgage-backed securities at UBS, which he left last year, has been marketing a 7,234-square-foot maisonette at 823 Park Avenue for exactly a year. He reportedly paid $20 million, and once wanted $24.75 million. Even though the tag came down in May to $14.5 million, the apartment hasn’t sold.

Meanwhile, Mr. Eisman’s family is looking for something larger. “Selling at a loss can be a very smart transaction, because this is a very good market to upgrade in,” said John Burger, a Brown Harris Stevens managing director. “It’s a very, very smart move to take a loss on an asset of lesser value—and upgrade.”

mabelson@observer.com

“What should you be paying for your place?” asked the event’s promotional materials, promising a discussion of “the fast-changing New York City rentals market, with an eye on new buildings, hot neighborhoods, how to find deals and strategies for coping and staying sane during the apartment search.”

But the evening’s primary piece of advice to curious tenants: Don’t rent, buy!

Curbed founder Lockhart Steele, moderating a conversation with appraisal guru Jonathan Miller and Prudential Douglas Elliman CEO Dottie Herman, opened by saying that they would be taking the evening in a somewhat different direction than originally promised. Using Mr. Miller’s Thursday “Three Cents Worth” Curbed post as a jumping-off point, they would consider the intertwined relationship between rentals and sales—a process facilitated by Mr. Miller’s rental reports, which debuted in July as the latest in the stable of formidable market analyses he does on Elliman’s behalf.

Mr. Miller said that he hoped to bring transparency to rentals, and to make rental/sales comparisons a matter of “apples to apples.”

But after some general reflections on the state of the market—first-time buyers have incentives; leases of small apartments lag—the panel seemed to serve only a glancing analysis of the New York apartment renter’s lot in life. They discussed instead the woes of developers, the challenges of the foreclosure market, and the timing of a potential rebound. “We’re in the sixth or seventh inning of the game,” Mr. Miller said.

So—what to do? Ms. Herman said that even with falling rents, she advised people staying in the city more than a year or two to buy. Leave a standing offer if your bid is accepted; buy cheap in an area priced high—surrounding properties will pull your value up. “Rentals are just throwing your money out there,” she said.

During the closing Q&A with the audience, a self-described “potential first-time buyer” asked whether emerging markets like East Williamsburg and Bushwick were worthwhile. Mr. Miller said that they were more volatile. The first-time buyer pressed: What if you could only afford to buy in an emerging market? Would it be better just to rent in Manhattan?

“I would buy,” Ms. Herman said. “Get in the game.”

She later recalled her father advising her to buy real estate instead of traveling to Europe.

Ms. Herman wore a white suit printed with roses, a pink scrunchie on her wrist, and a gold “D” necklace. Jonathan Miller, in business casual, was a jovial, avuncular presence; and Lockhart Steele, looking like a Google programmer in a button-down shirt, was  far less menacing than his badass, super-villain name would suggest.

Mr. Steele said that he hoped to host similar events in the future, and solicited audience members’ advice. After all, a panel like this represented a real-world version of blogosphere dialogue for Curbed’s devoted and interactive readership. He said that they had presold 50 tickets, but admitted that the recent Eater panel with Top Chefs was probably a bigger draw.

But what of the renters who can’t hope to buy? Was there anything to offer them?

“Find someplace fun,” Ms. Herman said after the panel. And then, she said, consider buying with friends.

mfischer@observer.com

What must have really bothered the brokers, this small batch in the running to have the odd honor of listing Bernie Madoff’s two-floor apartment between Park and Lexington avenues, is that they were all corralled together. “It was a strange and, frankly, slightly insulting way to handle it,” one broker there said. “Everyone in that room has pitched pretty important exclusives. I’ve never had to go on a cattle call before.”

Last year, when agents auditioned to list the late Brooke Astor’s Park Avenue duplex, they were interviewed separately in her famously lacquered library. It went relatively smoothly—even though they had to smile and nod while sitting in front of her scandal-stained son, Anthony Marshall, plus bankers from the firm that became Astor’s court-appointed guardians.

The broker meeting for the Madoff penthouse, which has been rumored to be going on the market since January, was stranger. “Everybody kind of wandered around the apartment, and they herded us into the living room,” another broker said. “I just don’t see how they can make an evaluation on who to use.”

There are a lot of options. According to three sources, brokers that have been contacted include Corcoran’s Sharon Baum (famous for her SOLD 1 license plate and its matching diamond brooch); John B. Glass and Caroline E.Y. Guthrie from the blue-blooded Edward Lee Cave division at Brown Harris Stevens; Stribling’s Alexa Lambert, who has handled sales at the Plaza; Sotheby’s top broker, Serena Boardman, and vice president Anne Corey; and Elliman’s Daniela Kunen and Sabrina Saltiel, who are listing the incarcerated Phillip Bennett’s Park Avenue duplex penthouse, plus a lesser-known colleague, Whitney Gettinger.

They came armed! Ms. Baum had Corcoran CEO Pamela Liebman with her; Ms. Lambert had her firm’s founder, Elizabeth Stribling; and Elliman CEO Dottie Herman was there along with the head of the firm’s Manhattan brokerage, Steven James. John Burger, the Brown Harris broker who told The Times this month that he’d offered to forgo a commission, was not there.

As it turned out, the meeting with the federal marshals was more of a group info session than an audition. “What they said was, ‘I wish we could give it to all of you,’” Mr. James explained. “‘Look and see what the product is; advise us on what we should do; here’s the deadline for the proposal, and may the best person win.’”

By the end of last week, brokers sent in their proposals for how they would market the place, how much they would list it for (their pitch can’t be too discouragingly low nor too misleadingly high) and what kind of commission they’d demand (which, as Mr. Burger’s offer showed, will probably be modest).

One of the agents there guessed that the penthouse is worth $8 million, but will sell for less because of its ignominy—and its condition, which, despite Mr. Madoff’s reputation for punctiliousness, is imperfect. “So not triple-mint,” an agent said. “That to me was incredibly surprising.”

“I thought it was eerie,” another said. “The place was left as if someone got out in the middle of the night. All the clothes were there, there was a note, there was a cup of coffee on, I think, his desk. The only that was gone were the photos: the picture frames had no pictures.”

mabelson@observer.com

“To me, this is fun,” Mr. Miller said. “I don’t do something unless it’s fun. I’m very childlike. I have four boys, and if they get a remote control car, I get a remote control car.”

Mr. Miller calls New York real estate a spectator sport—something to rehash at backyard barbecues (“Except New Yorkers don’t have backyards”)—and he’s given many more people a chance to see the game.

“We’re all about transparency,” he said. “That’s been my mantra, and I live and breathe it.”

Mr. Miller, CEO and president of Miller Samuel, has been in the appraisal business with his wife and sister since 1986. In 1994, frustrated that co-op sales information wasn’t made public, he started approaching the major real estate firms for access to their records. “Everyone nodded their heads and said”—not necessarily in so many words—“‘Well, what would you do in return?’”

The answer from Mr. Miller? “Nothing.”

He saw it as more of an “altruistic” venture, one that would make him a better appraiser and the public better consumers. At the time, Douglas Elliman had been experimenting with an in-house market study, and approached Mr. Miller to collaborate. He made it clear that his involvement was “an all-or-nothing scenario”: The reports had to be impartial, done “independently or not at all.” They agreed.

The real estate community was slow to understand the arrangement. Two realtors, whom Mr. Miller declines to name, held meetings informing their brokers that Miller Samuel had been bought by Douglas Elliman. It took two years, he recalls, to correct that mistaken impression.

His rigorously objective approach paid off, though: His sales reports have become required reading. Initially released mid-year and year-end, they eventually became quarterly; and reports on outer boroughs and the Hamptons supplemented the original Manhattan-only analysis.

“I’ve always wanted to do a rental study,” he said.

Prudential Douglas Elliman president and CEO Dottie Herman called it a logical next step; 70 percent of the city rents, after all. The team tossed the idea around for the last couple of years, trying to figure out the particulars. In the end, they took a familiar approach—the rental reports use the same metrics as his sales reports, reinforcing their dominance. No one before has analyzed rent per square foot rental-wise, Mr. Miller said, but it makes it easier to see the links between rentals and sales.

And he still does “at least 90 percent” of the spreadsheet number-crunching himself. Of course, he acknowledges, this could be a fault; there could be a more efficient system. But he also acknowledges his own wonkiness.  “Remember,” he said, “I’m somebody that likes to watch C-Span.”

Fortunately, real estate watchers seem as interested in Mr. Miller’s numbers as he is. “I was expecting interest, but the coverage was overwhelming,” he said of the response after he announced the rental report. “People were starving.”

Ms. Herman pointed out that the rental market often consists of the customers most in need of information—out-of-towners and recent graduates who don’t know what to expect. New Yorkers may not be fazed by $2,000 studios, she says, but “if you were in Kansas or Ohio or the middle of America, you would flip out.” And, too often, Ms. Herman says, the real estate business fails to provide comprehensible information, especially as compared to other industries’ tech-savvy accessibility. Consider something like WebMD, she suggested: “There’s lots of information, but then you have to figure out whether you’re dying.”

It’s an apt comparison, as Mr. Miller’s professed love of “pushing out content” has spawned a podcast, a Twitter feed, blogs and copious TV appearances. But while his numbers feed an Internet-inspired hunger for information, they’ve established their strength through a quality the Internet is conspicuously not known for—methodical impartiality.

“I have my name,” Mr. Miller said, “and that’s all I’ve got.”

mfischer@observer.com

It’s the stuff real estate dreams are made of! Annual broker awards, especially at a monolith like Elliman, are about money, status, competitiveness, salesmanship, hierarchy and, of course, self-celebration.

Yet Elliman, it turns out, does not appreciate it when real estate reporters try to attend. After a series of e-mails and phone calls last night with Elliman’s public relations team, I was turned away at the softly red-lit entrance to the 65-foot-high, 87-year-old ballroom today at 9:12 a.m.—first by one well-dressed woman, then a second nice woman and suited man came over too.

Elliman will release the winner list later today, so why should they care about reporters attending? One reason might be the well-covered 2004 ceremony at the Pierre, in which Michael Shvo essentially beat out his partner-turned-foe Dolly Lenz—she won broker of the year, but he was declared winner of “the all-time sales earning record in history.”

At the ceremony, Donald Trump reportedly called Ms. Lenz “one of the great killers of all time.”

Two days ago, I talked with Elliman president and CEO Dottie Herman. Does she remember the Lenz-Shvo tension? “Let me tell you something, there’s always tension; there hasn’t been a year there hasn’t been tension, it doesn’t matter who the people are,” she said.

"There’s a whole story behind that, but the truth is, there’s always tension. And if you didn’t have tension you wouldn’t want people in the company. Why would you want to have a company where people didn’t care if they were No. 92 or No. 9,000?" she said. "People make it like it’s a horrible thing. Everyone I know that’s good is always competitive. If you weren’t competitive, then something would be wrong, you’d be in social work. There are government jobs, there’s social work. In this kind of an industry, you want competitive people.

“It’s not about people being snakes necessarily,” Ms. Herman said. “It’s about people wanting to be at the top of their game.”

I asked about a rumor that Ms. Lenz, despite her continuously massive sales, won’t be No. 1 this year. “First of all, why would I tell you? Because that is one thing that no reporter will know.”

Today, three major brokerages released their market reports. Similar to last quarter, the results differ here and there. In both the Corcoran Group and Brown Harris Stevens reports, the average sales price for all Manhattan apartments (both condos and co-ops) dropped 5 percent. However, the Prudential Douglas Elliman report--prepared by Miller Samuel--showed an increase of 6.6 percent. And in that report, the average apartment has hit a new record price: $1.386 million.

But one significant area of concern could be the increased inventory of condos.

Traditionally, the large percentage of co-op apartments has worked as a safeguard in the Manhattan market, which has not been as investor-driven as other markets that boomed over the past few years. So will the increased inventory--which the Corcoran report shows jumping from 6,134 units to 9,619 units over the past year--cause buyers to pause?

"Anyone who has been playing the waiting game in the Manhattan--over the past five years--has come out on the losing end," said Pam Liebman, CEO of the Corcoran Group. "Buyers are very savvy. Buyers do take longer to make their decisions, because they have more time to see. But I don't see a huge downturn."

Indeed, a year ago there seemed to be much more of a rush to jump into a market that was witnessing ever increasing rates of appreciation.

Also, the drop in average sales price could be the result of less expensive units closing this quarter, according to Ms. Liebman. Indeed, some of the high priced units that have been reported as sold--at the Plaza or 15 Central Park West--will not be closing for at least another quarter.

For Jonathan Miller, president of appraisal firm Miller Samuel, his report shows appreciation is most categories, and should certainly not cause alarm. However, he did notice a few contradictions in the Manhattan market.

"Prices are rising and setting records in this quarter, yet the volume has dropped and inventory has risen," said Mr. Miller. "Buyers are not negotiating, so they are waiting longer. That makes inventory pile up."

"We're at a much slower pace," said Mr. Miller. "Appreciation has eased significantly. We're looking at rising rates and rising inventory."

And Dottie Herman, CEO of Prudential Douglas Elliman, remains confident that there will be plenty of buyers to absorb the inventory. "You're not going to steal anything, but you have to price things properly today," said Ms. Herman. "There are no fire sales going on."

But, again, this isn't a year ago.

"There is no more boom," said Ms. Herman. "The boom is done."

- Michael Calderone

Average Sales Price (2nd Quarter 2006/ 1st Quarter 2006)
$1,386,193/ $1,300,928 (PDE)
$1,212,453/ 1,258,420 (BHS)
$1,247,000/ $1,311,000 (CG)

Average Sales Price (2nd Quarter 2006/ 2nd Quarter 2005)
$1,386,193/ $1,317,528 (PDE)
$1,212,453/ $1,276,964 (BHS)
$1,247,000/ $1,284,000 (CG)

While we still love the last issue of Haute Living, there is already a new one out. This issue features some of the most powerful women in Manhattan real estate.

Find out all you've ever wanted to know about Pam Liebman, Dottie Herman, Louise Sunshine, and Elizabeth Stribling, who provides this story about breaking into the industry.

And what about each woman's forecast for 2006? Not surprisingly, they're quite optimistic.

- Michael Calderone

The story of Zillow.com has been, from start to finish, an anachronism: a stealth start-up formed in a whorl of rumor by an old god of the Internet boom (Mr. Barton founded Expedia.com); funded in a venture-capital frenzy; and launched far ahead of schedule as competitors—many of them old friends and business associates—got wind of the plan and raced him to the market.

The icing on the cake is that, this time, the whole thing is founded on speculation about one of the most hotly contested sectors of the economy: the real-estate market.

“Zillow.com today announced the launch of its beta real estate site, offering free, unbiased valuations on more than 40 million homes across the United States, with data on an additional 20 million homes. This includes most homes in the country, not just those for sale. All consumers need to do is enter an address.”

Creepy! The number it crunches out for the address you type in even has its own name: It’s the property’s “Zestimate.”

It will include historical value changes for each home, charted over one-year, five-year or 10-year terms; it will compare those value changes to value changes in the surrounding ZIP code, city, state or the whole country. It will find data on all comparable home sales in an area. It will offer satellite and aerial views of each home. And it will include individual data on each home, including the number of bedrooms, bathrooms, total square footage and the year built.

It’s free. You don’t have to identify yourself to get the information.

Is this what everyone was so nervous about?

Until the eve of the site’s launch, little more was known than the company’s name, its slogan (“Your Edge in Real Estate”), its $32 million in investment capital and the bona fides of the company’s founder. Now 38 years old, Mr. Barton revolutionized the travel industry with Expedia, and resigned as its chief executive in February 2003 after selling most of the company to media mogul Barry Diller.

He’s a name brand stepping into a burgeoning field of Internet entrepreneurs who want to cash in on America’s housing boom and increasing penchant for the kind of do-it-yourself financial planning that has already made a million millionaires on the Web.

And he’s a big threat to Manhattan’s brokerages, which through a combination of exclusive deals and keeping listing information out of public hands, have always maintained a tight hold on the Manhattan real-estate market.

“Whether it is one of my competitors or not, at the end of the day, there is no reason any of these sites should exist,” said Dottie Herman, chief executive of the New York brokerage Prudential Douglas Elliman. “We should never have had that competition, because we should have had it on our sites. We should have done it a long time ago.”

‘Shaking in their Boots’

But it took the slow siege of Zillow to get New York’s real-estate players grabbing for scraps of the future industry before it’s too late.

Can the brokerages compete with high-profile tycoons like Mr. Barton, who are willing to pour millions into the system to push the industry to be more Internet-based?

“It happened when Barry Diller decided to get into the business,” said Bradley Inman, founder and publisher of Inman News. When heavily financed power players enter the picture, “the traditional industry shakes a little in their boots.”

It all started late last year, when Mr. Barton suddenly became a fixture at local real-estate functions—a conference at the Times Square Marriott, a party in a Chelsea loft—and intensified when he gave an interview to Inman News.

“Hopefully,” Mr. Barton told the reporter, “2006 will be remembered as the year that Zillow.com showed up.”

At a conference he met the chief executive, of PropertyShark.

“Rich Barton said to me that he loves PropertyShark, and that honestly scared me,” said Rich Slack, of PropertyShark.

“It’s really frightening for a little company that we’ve just bootstrapped, to have somebody come along with $32 million and a gold-plated executive team that they have employed,” said PropertyShark founder Matthew Haines. “We’re trying to keep our cool.”

On Feb. 2, the Corcoran Group relaunched its own Web site with a sleek black home page, and added features that are standard in the new breed of real-estate search engines and databases: searches by school district or subway line, for example. (Another feature allows Web crawlers to arrange furniture in the property, using an online layout tool.)

Ms. Herman said her firm is preparing to relaunch their own Web site in a few weeks, and the chief executive claims that “it will have information that nobody else has in the city.”

On Feb. 7, PropertyShark, which assembles a wealth of property data pulled from public records for house-hunters and brokers, stepped up plans to advance its own real-estate Web service in major markets, including New York.

Last week, another Seattle-based startup, Redfin, launched a direct service that could cut into broker commissions. According to a source, Redfin plans to come to New York imminently.

“In the real-estate industry, a lot of the cost is going out of that equation,” said Paul Goodrich, managing director of Madrona Venture Group, which helped fund Redfin, where Mr. Goodrich is also the chairman.

On Jan. 31, Trulia.com launched in New York City, providing its easy-to-use searches through listings from numerous brokerages, while also accessing data compiled by real-estate appraisal firm Miller Samuel and PropertyShark. In addition, the Web site provides what are also referred to as mash-ups—hybrids of two different technology services—where the listings retrieved are then pinpointed on Google Maps.

And then there is Mr. Diller, whose RealEstate.com—which links customers to local brokers, provides search tools, and assists in the mortgage process through his conglomerate’s Lending Tree brand—is preparing to step into the brokerage business in some markets this year. Ironically, it was Mr. Diller who purchased the remaining shares of Expedia, allowing Mr. Barton to pursue his latest project.

Mr. Diller’s RealEstate.com currently brings in revenue by having brokers bid for potential buyers who have signed up with a customer profile. The customer is given a choice of four brokers, and if the individual closes with the broker, they can receive a rebate of $2,000 or more. In addition, consumers are also prequalified through Lending Tree as a way to unify the mortgage and buying process.

Later this year, the company plans to move into the brokerage business in some markets on the West Coast, which could be difficult, considering that the company currently brings in revenue from broker partners.

The Manhattan Project

In most of the country, individual markets rely on what is called a multiple listing service—a database of properties for sale which agents have access to. Manhattan doesn’t have one.

There is a listing service run by the Real Estate Board of New York, but it’s available only to licensed brokers. Approximately 300 member firms are expected to share their listings within 72 hours of receiving an exclusive to sell a property.

“If you are interested in buying an apartment, and you walk into any one of these firms—whether it is a one-person firm or a 2,000-person firm—they’ll have access to what’s available,” said Steven Spinola, the president of REBNY.

“There is a distinction in that we don’t have a database,” continued Mr. Spinola. “We don’t have a public Web site. We set rules for the cooperation of brokers. As a REBNY member, they are not only encouraged, but obligated to co-broke.”

In some precincts of the luxury stratosphere—the gilded corridors of Fifth, Park and Central Park West—the code is unlikely to be cracked by the likes of Zillow. (Observer challenge: Look today for a Zestimate on a Corcoran co-op listing in a Candela building on Fifth or Park Avenue; let’s see how we do!)

But large condominium developments, quickly emerging as a larger and larger part of the super-luxury market, are unlikely to be so immune to Mr. Barton’s surveillance.

If enough properties are gathered on a Web site without needing access to the REBNY database, brokerages like Corcoran and Prudential Douglas Elliman, which have increasingly depended upon expanding their listings down-market to stay competitive, could find themselves losing a lot of business.

For instance, if a buyer is interested in a finding a $1 million to $2 million home in the Upper West Side and checks Corcoran’s Web site, they would retrieve 51 listings. However, with another listings aggregation, PropertyRover, the same search yields 298 listings, from various firms. Then the buyer clicks on the listing they like and is directed to the company Web site that has the lead.

If a buyer uses Redfin to purchase a property—using the on-staff (and salaried) licensed broker, the startup will take 3 percent of the commission in the transaction. But the buyer gets a rebate of 2 percent, with Redfin pocketing the other 1 percent as its share.

The same transaction would otherwise have involved two brokers, with privileged access to the REBNY database—one for the buyer and one for the seller—each extracting a 3 percent commission from his client.

That’s half of the brokerages’ business.

The only way to protect themselves is for the brokerages to consolidate—to further clamp down on the exclusivity of their listings—and to create enough online features to entice home shoppers to begin their search for property on their Web sites.

With more buyers starting their searches online, each firm is vying to be the best place to begin by offering a user-friendly system that is packed with information. The city’s leading brokerages are sparing no expense in redesigning their company Web sites with more features, pushing BlackBerries on brokers.

And making partnerships with the new breed of real-estate firms operating on the Web.

Trulia started its work in California. But before entering the New York market they reached out to Manhattan brokerage firms.

Now venture capitalists are pouring millions of dollars into Trulia, and the company plans to bring in revenue through advertising—not brokerage. Phew!

“We’re going go be friendly with the brokers, to offer them services to compete with Zillow,” said Mr. Haines.

Mr. Haines’ company is partnering with Terra Holdings, which owns Brown Harris Stevens and Halstead Property, in an effort to provide real-estate data to potential Terra Holdings customers.

“I think the nature of real-estate companies has changed over the last few years,” said Jim Cahill, executive vice president at Terra.

Mr. Cahill said he also plans to incorporate subway directions into listings through HopStop, an online company that acts like MapQuest for public transportation.

“The public has more and more access to information than they’ve ever had. I think it is really important to give the consumers what they want, as fast as possible.”

The arrangement appeared to be an effort to combine forces against the increasingly hyped-up storm of Zillow. A press release issued by PropertyShark about its own plans in the coming months read:

“My understanding is that Zillow is out to disintermediate the broker and real estate salesperson …. Unlike Zillow, PropertyShark.com is focused on empowering real estate professionals, not disempowering them. We give professionals, and savvy consumers, the actual raw data, as well as an unprecedented level of depth which captures the unique nature of each piece of real estate and its value.”

“What these engines are doing is putting it together,” said Jonathan Miller, the president of Miller Samuel. Mr. Miller is one of the industry leaders in producing voluminous industry reports. Recently, he’s also been providing data and analysis regularly on both his own blog, Matrix, and the popular real-estate blog Curbed.

“They’re not replacing the brokers,” said Mr. Miller, “but offering a tool to navigate to the listings.”

And a tool for the brokerages to stay relevant.

“Way back in the late 90’s, we invested a small fortune in Corcoran.com,” said Pamela Liebman, chief executive of the Corcoran Group. “It is much easier to have that capable and experienced broker leading the charge for you,” said Ms. Liebman. “I can also probably go on the computer and find out what’s wrong with me when I have a head cold, and order my prescription from Mexico over the Web. I’m not going to do that, I’ll call the doctor.”

Ms. Herman does not think the influx of real estate dot-coms will tap into the traditional brokerage business.

“They’ve been telling me that for 10 years,” said Ms. Herman. “At the end of the day, I don’t really believe that our company even competes with them. It’s apples and oranges.”