(FORTUNE Magazine) – Internet time--no exaggeration, this stuff moves so fast, you gotta figure out a way to clone yourself. We're doing a deal a minute--raising money, signing affiliates, negotiating content, hiring people, building the company--it's crazy, and it all happens overnight! These companies have to be put together so fast.... Look at us or Amazon or eBay--overnight you're into stuff that used to take five years!"

Tom Jermoluk knows about fast. Back at Silicon Graphics he advanced in four years from managing nobody to managing, as president, 11,000 people. But now, at 42, he's CEO of @Home Network, a provider of Internet services via cable TV connections--and this is something else.

He's running a successful e-corporation, a company built around the Internet, which places him among America's newest and most luminous business elite: e-CEOs. They include many of the youngest and richest executives anywhere (although they don't like the word "executive," with its old-economy feel). Whatever your business is, they're affecting it. And if they're doing more than that, if they're changing the world and altering the future of life on earth--as they all absolutely believe they are--then you have to wonder: What kind of person thrives in this role? What does it take to be a successful e-CEO?

Spend time with them, talk with them in fast-moving conversations, visit them in their modest, espresso-scented offices, and the picture you get is clear. You realize first that while an e-CEO's life is different from yours and mine in a hundred ways, the biggest difference, the one they just can't get over, is speed. "You're driving too fast--you feel the exhilaration and the threat--you must turn left and right at death-defying speed without blinking--never blink--if you go up and down with the news, you'll never make it," says Roger Siboni, CEO of Epiphany, which creates software to help e-corporations get the most from their customer data. He was COO of the KPMG consulting firm and had worked with Silicon Valley clients for 20 years. But this is faster: "You have to be deadly, brutally honest with yourself and others because if you let a problem fester a day or two, you'll see someone in your rear-view mirror coming after you."

Example: Ziff-Davis announced last year it would sell shares in ZDNet, a collection of its Websites, likely giving ZDNet a hypervalued stock with which to make acquisitions. (Shares began trading on March 31, 1999, and ZDNet now has a market cap of $2.6 billion--about $1 billion more than Ziff-Davis.) Halsey Minor, 34, is CEO of CNET, an online competitor providing technology-product reviews and data, and he figured ZDNet would go after some companies he was interested in. "So we bought three companies in three weeks--we had to before ZD went public." Minor was lucky--many e-corporations go public before competitors can react. DoubleClick, a Manhattan Internet advertising firm, floated stock just 90 days after deciding to do so. Remember when IPOs took nine months?

"I always run through the office," says Amazon CEO Jeff Bezos, 35. "I mean, physically I'm a little bit hyperkinetic. That's why I like this environment." Hyperkinetic seems an appropriate speed if, like Bezos, your company has a $32 billion market cap and has never earned a dime. Apparently insane stock valuations are a unique challenge for e-CEOs. Those towering market caps are built on foundations not of reality but of expectations, so a mere change in Wall Street psychology could annihilate a company's value. All CEOs have to master the expectations game, but e-CEOs have less to work with and more at stake.

Disasters do happen. Everyone's favorite example is PointCast, purveyor of "push" technology that places constantly updated information on your screen all day long. Just two years ago this was very hot stuff. Then customers realized that push clogged up their corporate networks and they ordered employees to get PointCast off their PCs. The company didn't adapt sufficiently; it's a shadow of what it was.

In different ways, e-CEOs all say the same thing: This is business in real time, where nothing can wait until tomorrow or even until after lunch. "Because the Internet lowers barriers to entry, it amplifies weaknesses," says JoMei Chang, whose company, Vitria Technology, makes giant software systems that tie together other giant software systems. "There's no place to hide. It forces you to be on your toes every minute, every second." That's why e-CEOs seem to carry every known electronic business device: cell phone, two-way pager, Palm, laptop. Michael Dell says he's found "one way to spot an e-CEO for sure: Does he or she get bandwidth-separation anxiety?" That is, do they get crazy when deprived of high-speed connection to the rest of the planet? "It happens to me," says Dell. "You kinda get the shakes."

Yes, says Yahoo CEO Tim Koogle, this is something new. He has a better basis for comparison than most e-CEOs, being all of 47; he sold a business to Motorola and worked there for a decade. How does this stack up? Looking tired but happy, he says, "This is a fundamentally different kind of experience. It's pretty consuming."

The reason the e-world moves so fast is also the main reason the e-CEO has to be a different breed: There's nothing there. Nothing tangible. In the memorable distinction drawn by Nicholas Negroponte, director of MIT's Media Lab, most of these companies don't deal in atoms, just bits. "What we do is pure mind," says Intuit CEO Bill Harris, whose company makes Quicken and other financial software, distributed increasingly over the Net. Says Koogle: "There's nothing physical--it's all intangible. I love it."

Even media companies, whose businesses are based on intellectual property of various kinds, are linked to substantial physical assets: presses, trucks, studios, transmitters. But now stop by the place where a big chunk of Yahoo's Website originates, to the extent that it can be said to originate anyplace: a small basement room in Palo Alto, with three flattish boxes atop one another, each about two feet square, displaying a small sign--DO NOT TOUCH. From here come millions of page views a month and millions of dollars in monthly ad revenues. Yahoo doesn't even own the servers; they're outsourced.

In an intangible world where maybe you can't do everything in no time but it seems you can, e-CEOs constantly labor to focus their companies. "The No. 1 thing you need is a clear vision of your role in the Internet economy," says CNET's Minor. Is this really different from other businesses? It is--every company needs focus, but there's a good reason e-corporations need it more than others. Think of it this way. When International Paper turns on a new paper machine, which may be larger than a football field and cost $800 million, thousands of employees know exactly what they'll be doing for years: making more paper and selling more paper. If a bright employee thinks IP should get into aluminum, it doesn't matter: The machine makes only paper. But at Yahoo, Intuit, or eBay, where the primary capital equipment is brainpower, employees can start pursuing radically different strategies in an eye blink. ("Maybe we can devote part of the site to...Satanists! That seems like a growing market.") Soon your assets are utterly uncoordinated, unless the e-CEO reinforces the strategic focus relentlessly.

That's even more crucial now. With this sector white hot, e-CEOs find their companies barraged with money and ideas. "We get a thousand opportunities a day," says Kevin O'Connor, 38, CEO of DoubleClick. "Strategy is half deciding what to do and half what not to do." Says Koogle: "You have to be able to say no to $10 million," which he apparently has done, though he won't say who offered it.

E-CEOs use the word "evangelize" a lot, which makes sense in a fundamentally new business that many people don't understand. "Evangelizing? I spend way more than half my time on that," says John Chambers, CEO of Cisco Systems. Unlike most e-CEOs, he runs a long-established, hugely profitable company, yet even he has to keep flogging his big idea, which is the vast scope of the Internet revolution. "You've got to evangelize the concept," he says, and immediately begins doing so at the fastest rate of speech you've ever heard: "Over 70% of our customer support is provided via the Net, and..."

The e-CEOs who have come over from the old world can't believe the amount of hyping they must do. "I didn't realize how much time would be devoted to positioning the company," says Roger Siboni, the ex-KPMG chief who runs Epiphany. "It was the biggest surprise." Tom Jermoluk of @Home figures "at least 50% of my job is being an evangelist--with our employees, the Street, the press, my partners. There are up times and down times, but it's keeping everybody believing that there really is a pot of gold at the end of this rainbow--I don't mean in a money sense, I mean in the accomplishment of the vision." Well, of course. The pot of gold in the money sense was reached long ago: @Home's market cap was recently $19 billion.

Preaching also helps soothe the demographic cohort e-CEOs care about most. "I gotta tell you that the Generation-X people, way more than our generation of baby-boomers, really, really want the evangelizing," says Jermoluk, who's known as T.J. around the office. "They crave it--understanding what it is that they're a part of and how it makes a difference."

That evangelizing is so important seems appropriate, given that the e-CEOs run companies built largely on faith. It's hard to remember, but just two or three years ago the Net provoked far more skepticism than excitement. "What you needed was to be a believer," says Minor. "You had to buy the dream. There was no money, and there was intense cynicism. You had to have unshakable faith that the Net would turn into something."

Even in today's Net euphoria, that's still what e-CEOs need, because they don't think they're one-tenth of the way to where they want to go, and getting there will require more frightening leaps of faith. After all, says DoubleClick's O'Connor, the nature of fundamentally new ideas is to make you wonder: "Is this psychotic or revolutionary? It's a pretty thin line." Does he ever think, for just a moment, that this whole e-thing might be psychotic? "Never. The belief is in your DNA." As it must be. Stuart Burch and Tuck Rickerds are headhunters with the Russell Reynolds firm who do a lot of searches for e-CEOs. The No. 1 quality they look for is "an ability to visualize a future very different from what exists and be passionate about it."

The No. 2 quality they look for is "ability as a real-time decision-maker." In business--in life--you never have all the data you want when making decisions, but in the Internet world the problem is much worse. Because this world moves so fast and is so intensely competitive, e-CEOs make decisions every day without nearly enough information. Due diligence? It's a nice concept. But these CEOs admit (without wanting to be quoted) that they buy whole companies without knowing as much as they should. What else can they do? In the Monopoly-money world in which they operate, if they don't buy this morning, a competitor may this afternoon. "This demands a level of risk tolerance that's a little different," says Koogle. Adds Intuit's Harris: "You have to be willing to let go of things you know in an environment where you're plunging into things unknowable."

Some people thrive in those conditions; others stagnate. It's a matter of temperament, which is one of the most important factors in whether an e-CEO succeeds. Faith helps. If you're certain where things are heading, then you use that in decision-making "to envision the outcome and its inevitability," says Harris. Example: "Will people do their personal finances in an interconnected electronic way? Yes--inevitably yes. So you just keep moving toward that."

Harris, like a lot of e-CEOs, is more marketing guy than techie (his background is mostly in publishing). But the group also includes plenty of computer engineers, like Koogle and Jermoluk. Neither type predominates, because the job requires a mixture of infotech literacy and brand-building smarts, a whole-brain assault force that most business people can't muster. Many e-corporations don't try to be cutting-edge; instead they apply available technology to an idea they're convinced is a killer. But CEOs still need a sense of the technology. For one thing, the success of their business may depend on technology choices they make at the very beginning--customer service at Amazon and prompt delivery of dolls from eToys, for example, are possible because these companies chose the right kind of software to mine data reflecting customer preferences and to manage distribution. It also matters because, remember, e-CEOs are making decisions too fast with insufficient data--they need a gut feel for what technology can do.

At the same time, they know that while the technology is necessary for survival, it isn't sufficient for victory. That requires the ineffable human connection represented in a brand. Why? "On the Net, consumers have a lot of choice, so brand wins," says Kevin O'Connor. "Too much information means brand is important," says a smart e-CEO who doesn't want to be quoted because his company is in a pre-IPO quiet period. "You have to think of yourself as a portal that caters to a community." There's another of those words you keep hearing--"community." The theory is that well-run sites will become, through a virtuous circle, electronic gathering places that people go to in part because of the others who go there. That's eBay, for example, where auction addicts buy from and sell to one another. If eBay turns out to be a site that holds its surfers, then it might--perhaps--someday justify its stupendous valuation (recently $22 billion).

So the successful e-CEO, while technically savvy, must also understand the squishy-soft world of consumer behavior. Venture capitalists, whose money is at stake, "always favor someone with brand experience outside the space," says headhunter Burch. E-CEOs with at least a dollop of consumer-branding experience include not just Bill Harris but also Intuit co-founder Scott Cook (Procter & Gamble), AOL's Steve Case (P&G, PepsiCo), eBay's Meg Whitman (P&G, Disney, Stride Rite, Hasbro), and eToys' Toby Lenk (Disney).

E-CEOs must spend a lot of time recruiting, since their companies are growing fast and run on brainpower. Amazon's Bezos puts recruiting near the top of his list; he says, "I look for a willingness to change direction and to admit mistakes," the prerequisites of speed. Yet even in Net companies, recruiting isn't as easy as you might think. No one can get fabulously rich on stock options if the stock doesn't trade, and many e-startups never make it to the IPO. On the other hand, if the company is as established as, say, Yahoo, prospects figure the big wealth may have already been made.

What makes recruiting hardest is that the people who understand e-business are rare and can go wherever they like. "The opportunities are endless and unbelievable," says Epiphany's Siboni. "These people can do anything they want. They're all smart, all following the dream. It's as competitive to get a great person as it is to get a big new account. And it's more important to get the great person." After you get them, keeping them isn't easy. With new e-corporations sprouting every day, fresh opportunities beckon just a little way up or down the Valley's Route 101. Now, says Siboni, "you must always be a great place to work, or they'll leave."

Bringing people in from other industries, at least, is easier than it used to be. Kevin O'Connor remembers trying to

persuade Wenda Millard, a 21-year publishing veteran, to join DoubleClick way back in 1996. He did his best, but might not have succeeded without her kids' help. When she told her two sons about the job, "My 9-year-old's eyes nearly dropped out of his head," she recalls. His only question: "Mom, do you realize how totally cool that would make you at school?" Her 7-year-old advised, "Mom, you really need to brush up on your computer skills anyway." Then a comment no parent could shake off: "You know, Mom, I would be very proud of you." Today she's happy she said yes, and so are her kids. By the way, her options are in the money by $25 million.

That is still the e-CEO's biggest friend in recruiting wary outsiders. Headhunter Tuck Rickerds says these days his sales proposition is simple: "My first words are, 'Do you want to retire in 20 years or in two years?' " It usually works.

The thing is, many e-CEOs don't retire in two years, even though they could. They press on, apparently addicted to the stress and the rush and even the danger of being blind-sided by competitors or market forces they missed. They understand this danger better than anyone and are obsessed with avoiding it. It's why one more word you hear everywhere is "paranoid."

If e-CEOs had to wear a lapel button (and if they had lapels), it would say PARANOID and PROUD. The word gets its currency from Intel Chairman Andy Grove's book Only the Paranoid Survive; the concept resonates with virtually all these CEOs. So far they've been the linebackers creaming quarterbacks looking in the wrong direction. Now they're trying to look in every direction at once. David Bohnett, founder of GeoCities, which Yahoo recently bought, explains: "We're paranoid because we don't want anyone doing to us what we did to others."

They also understand that in this new industry the odds are against their survival. Jeff Bezos compares the rise of the Internet to the Cambrian era in evolution: "That was when the earth had the greatest rate of new life. What people don't know is that it also had the greatest rate of extinction."

Talk of the Cambrian era leads to a big question that must be asked: Despite the e-CEOs' assertions, is anything actually new here? Is being an e-CEO really such a singular experience? Or are these a bunch of mostly young business people discovering how extraordinarily hard it is to run a company and believing, like typical self-centered baby-boomers (they're all baby-boomers), that no one has ever experienced it before?

It isn't hard to guess the thoughts of old-line CEOs as they read this. "So these kids have to make fast decisions with limited information--oooh, just imagine! And they have to understand technology as well as brands! Jack Welch wouldn't know anything about that. They need faith. Well, John D. Rockefeller needed faith--he invested millions in refineries when no one knew if the oil in the ground would last a week." You can make similar arguments about all the other qualities of an e-CEO. Bottom line: Wouldn't any good CEO make a good e-CEO?

That's the skeptics' case--but it isn't persuasive. Be as tough and cynical as you like, and you still can't deny that the e-CEO's experience is new. There's the speed, which changes every part of the job and imposes unprecedented demands. Never before have we seen so many companies explode from birth to market capitalizations in the tens of billions of dollars so fast. Quickly, often at tender ages, these CEOs must learn all the parts of running giant, publicly traded corporations--strategy, operations, finance, regulation, accounting, legal, Wall Street--while growing at double- or triple-digit rates. Above all, they must feel, as traditional CEOs don't, the nature of a new kind of economy with few or no tangible assets, where things change as fast as electrons move and synapses fire.

This isn't the whole story. As all these CEOs point out, we're still in the earliest moments of an economic revolution. Five years from now--excuse me, five months from now--some of these companies may be withered relics, their market caps decimated, their names spoken in the scornful tones the Valley now reserves for PointCast and a few others, their CEOs fired by angry directors, their fatal errors regarded as obvious and foolish. If so, it's entirely possible those errors haven't even been committed yet. The portrait of the successful e-CEO is still a sketch.

Some people believe the world's great new dominant companies will emerge from today's e-corporations. "The next General Electrics or Disneys or Microsofts--they're in this group," says O'Connor. They may well be. Or maybe the nature of the e-world is different, and no company will remain dominant for decades. If you're an e-CEO, you don't know. You can't. But you know beyond doubt how precarious is the glory of this moment. You know that your enormous wealth may be fleeting; it may evaporate before you can turn it from paper into cash. By the nature of the Internet, you may fight your world-changing fight all day, every day, until you've burned every erg of your considerable energy and then, like any ordinary prey species on the savannah, be devoured the moment you try to get a little rest.

And it can happen in an instant.

In its relentless demands, its uncertainties, its stellar highs and hellish lows, its revolutionary thrill and endless promise and killing pace, most of all in its law-of-the-jungle mercilessness, the e-CEOs' experience looks different from anything we've seen before.

As Tim Koogle says, "It's a good thing we all like it."

REPORTER ASSOCIATES Jane M. Folpe and Tyler Maroney