(FORTUNE Magazine) – At the cable industry's annual confab in Chicago, the place to be is, well, anywhere Brian Roberts is. As the Comcast CEO cruises the convention center's carpeted halls on a cool mid-June afternoon, executives who sell technology and television programs to Comcast--or would like to--schmooze shamelessly, some trotting double-time to keep pace with the fit, 6-foot-2 Roberts. During a televised segment Roberts is broadcasting to Comcast employees from the trade-show floor, Microsoft chairman Bill Gates drops by for an on-camera visit. Entrepreneur and Dallas Mavericks owner Mark Cuban--not exactly a retiring guy--patiently hangs back while Roberts finishes a conversation, just to say hello. Only singer Michael Jackson, who makes a bizarre appearance (does he make any other kind these days?) to promote an upstart cable network, manages to steal the spotlight. But even that lasts only a few moments. As soon as Jackson flees the scene, it is back to The Brian Roberts Show.

And why not? Jackson may be the erstwhile King of Pop, but Roberts is very much the reigning King of Cable. As a result of Comcast's acquisition of AT&T's substantial (and struggling) cable television properties, completed in November, Roberts now presides over the nation's largest cable system, a formidable cross-country network that includes franchises in major markets such as Chicago, San Francisco, and huge swaths of the East Coast. With 21.3 million subscribers, Comcast is double the size of its nearest rival, Time Warner Cable--of which it owns 21%. Comcast's pipes aren't just dominating TV, either: Through acquisitions and relentless marketing, the company has become the largest provider of high-speed Internet access, one of the few technologies still captivating consumers and capturing their cash. It controls cable modem service to four million homes, about 20% of the entire American broadband market. From $21 billion in market cap five years ago, Comcast has grown into a $70 billion behemoth.

And now the company has cleared the decks for even more deals. In early July, Comcast agreed to sell its 57% stake in home-shopping channel QVC to John Malone's Liberty Media in a deal that values the cubic-zirconium-hawking network at $14.1 billion, at the high end of analysts' estimates. The deal calls for Comcast, which helped launch QVC in 1987, to receive $8 billion through a combination of stock, notes, and cash, a tidy return on its $385 million investment. (Malone, meanwhile, may be rethinking his bid for Vivendi's entertainment properties, for which the French hope to fetch at least $11.5 billion.)

Meet America's newest media emperor. Unlike rivals who are hamstrung by debt, weak management, or--in many cases--both, Roberts has power, cash, customers, and a growing ability to exploit them all. The proceeds of the QVC deal can be used to reduce his company's $27 billion in borrowings. He can sell his stake in Time Warner Cable when it goes public or try to swap his stock for additional cable systems. Even Washington is on his side: Regulators are likely to lift rules that limit the amount of cable systems an operator can own. He can leverage his improving balance sheet to buy more cable, invest in new media properties, or perhaps launch his own entertainment networks. And he's firmly in charge: The Roberts family has 33% voting control. More stunning, he's managed to bring Comcast to the top in just seven months.

Yet Brian Roberts is the most unlikely of moguls. At 44, he is a cable-industry lifer. He shuns the spotlight, chooses his words carefully, and purposely avoids the vision thing. A technophile who stays in constant communication via his two-way pager, Roberts is happy to talk about deals but lights up when detailing the latest gadgets at a Japanese consumer-electronics show. He's equally comfortable promoting not just Comcast but his entire industry. In 1997 he suggested that Bill Gates invest in cable--and received a $1 billion Microsoft investment in return. Around the same time he created a buzz at Herb Allen's Sun Valley conference by chiding Intel's Andy Grove for suggesting the telcos' version of high-speed service could win the broadband war over cable modems.

Roberts's talent for playing his cards close to his vest is driving his competitors crazy. The company is already using its considerable buying power to neutralize mighty programmers--including influential companies such as Disney and AOL Time Warner (parent of FORTUNE's publisher)--by seeking volume discounts on the fees for their cable channels. In other areas, though, Roberts's power, and his reluctance to explain what he'll do with it, have caused intense speculation. Telecom executives, who have watched cable trounce DSL in the broadband arena, are nervously waiting to see how aggressively Comcast will deploy voice service over cable--fearful that this group will figure out what AT&T never could when it owned cable lines. And with the company's huge customer base, any Comcast-launched channel or Internet offering would become an instant competitor of the usual sources of such content and services.

Important people are lining up to get on Roberts's good side: When former Vice President Al Gore began pitching a liberal cable network this spring, one of his first stops was Comcast headquarters in Philadelphia. Motorola, a big maker of cable set-top boxes, used to simply sell its existing products to Comcast. A month after the AT&T deal closed, the equipment manufacturer met with Comcast executives and asked, "What do you want us to make?"

Roberts is taking that question and turning it around. Instead of setting a course, he's surveying the industry to see where to go next. In a series of interviews with FORTUNE, Roberts preferred to talk about potential partnerships and alliances rather than specific strategic moves. The CEO figures that as big as Comcast is, the ideas will come rolling in from the very people who are pulling at his elbow in Chicago and dropping by in Philly. Better to pick from the best of their visions than have to come up with his own. "You don't need to have all the answers all the time, but you do have to be curious and opportunistic," he says.

This isn't to say Brian Roberts simply plans to wield the largest rubber stamp in the entertainment world. He has a few ideas about the kind of services he's looking for. He likes to talk about the "personalization of television," the idea that viewers will consume television programming much as they access information from the web: in increasingly personalized nuggets. He and Steve Burke, a former Disney executive who joined Comcast five years ago, are trying to secure view-on-demand rights not just for movies but for all TV programming. Roberts is also intrigued by the growing use of Internet Protocol in cable networks, allowing all data, voice, and video traffic to travel across networks as interchangeable packets--though he freely admits he doesn't know what new services that will translate into. And that's okay by him. "There are so many business opportunities developing," he says. "My job is to encourage and stimulate that development." Plus, he figures, his first priority is making sure Comcast's biggest bet ever--its purchase of AT&T--actually pays off.

When that deal was announced in December 2001, it rocketed Roberts to the top of the industry but hardly made him a leader. In addition to its $25.5 billion in stock payment, Comcast took on $25 billion in debt--more than tripling its debt load. And for what? The Ma Bell properties were a mess. AT&T's original plan was to use cable to break into the local-phone market controlled by the regional Bells. To get there, it spent aggressively on upgrading its systems, many of which were outdated dogs acquired from Tele-Communications Inc. It also inexplicably paid programmers more for their content than some of the industry's smaller operators, including Comcast. Worse, the phone company was ceding subscribers to satellite competitors at a much faster rate than some peers: In 2002 it shed 500,000 customers, almost 4% of the homes it served. Not surprisingly, AT&T had around the lowest cash-flow margins in the industry, dipping to 16%, compared with Comcast's then 40%-plus levels. Most in the cable world thought they wouldn't hear from Comcast for years as it struggled to right its acquisition.

Roberts quickly set to work. He assigned Burke, who oversees the company's cable business, to the task of "Comcastifiying" AT&T cable. That meant decentralizing operations, giving people in the field more autonomy--and more responsibility--for achieving financial targets. Burke immediately trashed AT&T's strategy, halting all efforts to sign up new telephone customers--a low-margin business--and pushing hard to win back bread-and-butter video users. He spent on upgrading old lines for digital and high-speed service, key to retaining cable customers, but also led an exhaustive inventory of AT&T's systems that revealed that some networks it thought were obsolete had actually been upgraded--AT&T had simply failed to label them properly. And he raises prices on digital services. As a result of those early efforts, Comcast has already made considerable progress. The company says it expects the former AT&T systems to achieve cash-flow margins of 32% in 2003.

But what's really gotten investors excited is Comcast's financial discipline. Even before the QVC deal, Comcast is set next year to achieve positive free-cash flow--operating cash flow minus capital expenditures, interest, and taxes, an all-important measure of financial health. The picture only improves if Comcast applies all its after-tax proceeds from the QVC sale to its current debt load. The cable operator could end the year with $20 billion in debt, a modest three times earnings before interest, taxes, depreciation, and amortization. That would give it one of the strongest balance sheets in the industry. "Comcast management is a breath of fresh air," says Craig Moffett, a cable analyst with Sanford C. Bernstein who has an outperform rating on Comcast shares. "They are operators first and foremost. With the rest of the media industry, it is deal first, operate second."

Comcast hasn't always been that way. Early on, the company was built by someone always eyeing the next great deal. To find him, walk through the glass door at the front of Roberts's office. There, dressed in his standard bow tie, sits the man who is still encouraging Brian to think big: Ralph Roberts, Brian's 83-year-old father. A classic entrepreneur who once had a business making men's belts and jewelry, Ralph is officially chairman of Comcast's executive and finance committee (former AT&T CEO Mike Armstrong is chairman of the company). Unofficially, though, Ralph is Comcast's soul. He started the firm in 1963 by acquiring a cable franchise in Tupelo, Miss., and kept acquiring even as many of his entrepreneurial peers sold their systems. The elder Roberts started small, buying mom-and-pop operations, and worked his way up to Westinghouse's Group W cable properties, which Comcast acquired in the mid-1980s through an alliance with Malone's TCI. While other cable systems were toying with content, Roberts did that and also moved into commerce over cable. He helped start QVC--which later attracted a major investment from Malone.

Such alliances between the Robertses and Malone underscore the incestuous nature of the industry--but they also illustrate the Robertses' toughness as dealmakers: Most people walk away from negotiations with Malone scratching their heads--many unhappy. Comcast, on the other hand, seems to have done well in its dealings with Malone. For evidence, look no further than the QVC deal, in which Comcast fetched a fantastic price for a mature business.

As Roberts built his company, he never knew he'd have the chance to hand it over to one of his five children. As a strait-laced teenager ("He didn't sneak off and smoke pot or anything," Ralph volunteers), Brian Roberts worked in a Comcast office stamping the coupon books customers presented when they paid their bills. But just before his graduation from the University of Pennsylvania, he begged his father for a full-time job at Comcast; Ralph relented, on the condition that the young man start at the bottom. His first job: climbing poles and installing cable. He wouldn't have to climb much higher. At the age of 30, he succeeded his father as the company's president. "He's perfectly seasoned for this job," Ralph Roberts says. But it isn't just his last name that makes him a good leader, he adds: "If he was obnoxious, he wouldn't have the job."

From the start, Brian Roberts was fiercely protective of some aspects of Comcast's heritage. He says he resisted pressure from his management team to change Comcast's original logo, a square (representing a TV) with the company name in retro-looking blocky letters. To Roberts it symbolized the company his father had built. "I was 9 years old when my father came home with a yellow pad" with a sketch of the logo, Roberts recalls. "I remember him asking me, 'What do you think of this?'" Ralph, characteristically, was one of the biggest advocates of the new design, adopted in 1999, which features the company name in red lower-case letters. "I thought we needed to be more contemporary," declares the elder Roberts.

The days of debating logos are now long gone, of course; Brian's issues today are much tougher. Comcast says it is committed to chopping some $270 million out of the roughly $4 billion a year it spends to fill its pipes with movies, news, and sporting events. Sounds simple enough: Most companies that get bigger try to finagle volume discounts from their suppliers. But Comcast isn't dealing with just any set of suppliers. Roberts instead is taking on the likes of Disney's Michael Eisner and News Corp.'s Rupert Murdoch, media moguls who have enjoyed great sway over the cable operators because of their ratings-grabbing cable channels.

It's at Eisner's ESPN that Roberts will have his most visible test. ESPN has been asking cable operators to pay a 20% annual increase for its shows, arguing that Comcast and others get plenty of value for the roughly $2 a month per subscriber they pay to air ESPN. Comcast isn't about to debate the merits of ESPN's programming; it just wants a lower price. "We spend more on programming than any other cost," says Burke. "We would be crazy not to worry about these increases." Then, retreating into Comcast mode, he adds, "That having been said, we think these matters are better settled privately."

Others in the industry are doing their best to fan the flames. At Liberty Media's investors' meeting in May, Malone described with relish the role the younger Roberts now must play: "Brian has the mantle of being the defender of the cable industry and the consumer against the outrageous demands of greedy broadcasters."

Tensions between programmers and cable operators erupt every time the parties renegotiate, and neither side ends up looking particularly good if they let matters escalate. When AOL's Time Warner Cable division pulled Disney's ABC-owned and -operated stations off the air in 2000, both sides ended up looking like bullies. This time around, however, power seems to be shifting in Comcast's favor. For one thing, Roberts won't alienate his customers by yanking their favorite shows. "We haven't taken a broadcaster off the air," Roberts says. "When we were threatened with the same situation as Time Warner, we said, 'You are going to have to sue us to make us drop your station.'"

Another power play is that Roberts is quietly exploring his own programming options. Comcast reportedly is interested in a stake in Cablevision Systems' regional sports networks. Another scenario making the rounds on Wall Street is that Comcast eventually could team up with Rupert Murdoch's Fox to secure rights to broadcast NFL games--gaining huge leverage over ABC and ESPN, which currently broadcast Monday night and Sunday night games, respectively. And then there are persistent rumors that Comcast may make a bid for Disney.

Comcast, however, is sticking to its mantra of incubating--not inventing--new businesses. "We don't have to buy a movie studio or a television network or a cable channel," says Burke. "We can create value by starting things from scratch or working with entrepreneurs." Earlier this year Comcast agreed to invest with radio-broadcasting company Radio One in a new television network for African-American viewers. "We like to think we're really good at what we do," says Radio One CEO Alfred Liggins, whose company will act as managing partner of the venture. "But they could have launched an urban cable network on their own." The company followed similar models when it helped start QVC. Among its other content holdings, Comcast owns stakes in E!, Style, the Golf Channel, Outdoor Life, and G4 (a gamers channel), as well as controlling stakes in the Philadelphia 76ers and Flyers. New businesses are on the way: "I think we'll surprise people," says Burke.

They'll have to do better than that. With the AT&T systems on their way back, Roberts needs to deliver more than just new channels and better deals. Plenty of investors still wonder whether cable is a good investment at all, given the industry's history of huge capital investments and delayed promises of free-cash flow and profitability. Futurists say new technologies, such as broadband wireless services, could disrupt the cable business and force yet another major network renovation. Even more pressing, competition in the media and communications landscape is getting hotter. Recent FCC rule changes that enable media giants such as Viacom and AOL Time Warner to acquire more television stations and other media properties could hurt Comcast by giving the programmers more leverage. And things will only get tougher now that DirecTV, one of the cable industry's most potent rivals, is likely to end up in the hands of Rupert Murdoch's News Corp.

Online, things are heating up as well. The company expects to end the year with 5.2 million broadband subscribers, but many signed with Comcast by default--cable's chief rivals, the Baby Bells, were nowhere to be found. Now the phone companies are cutting prices and improving services. SBC Communications, which competes with Comcast in markets such as Chicago, Detroit, and San Francisco, has teamed with Yahoo to create a broadband portal with some sizzle. Verizon, which competes in the Northeast, is exploring plans to drag fiber to people's homes, creating a much faster connection than available over cable.

Roberts appears unfazed by becoming the chief target in both broadband and cable. "For over ten years cable has been a competitive business, and we're a better company today because we have to be," he says. "There's no reason we can't be more successful in the years ahead, because we have a superior technological platform."

To prove that, Comcast just unveiled a new version of its broadband portal. And it's weighing when and how to make its long-awaited push into the phone companies' core business: local phone calls. The company has 1.4 million local-calling customers it inherited from AT&T, but it has yet to announce a big expansion of the service. Roberts says he is waiting for Internet Protocol technology for telephone service to mature. But he says he'd also like to roll out something slightly different from what the Bells--and Comcast--can offer today: perhaps a video phone service or some other product that tightly integrates voice and data services.

Just don't look for Comcast to invent those products and services. (Hint: If you've got a hot IP technology for cable, get to know Philadelphia really well.) But being the first to push such technology is going to be a big step for the company, which traditionally has let the likes of Time Warner Cable and Malone's TCI take the lead. "We have the opportunity to genetically rewire ourselves," Roberts says during a conversation at the Chicago trade show. "To do this, we have to be willing to take risks and make some mistakes." A few minutes later, Roberts is out the door for an awards dinner. As he makes his way through the convention hall for the umpteenth time, he is greeted by a few more industry heavyweights; some attendees nudge each other knowingly as he walks by. If it seems as though everyone in the cable industry is watching Roberts--that's because they are.

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