“I heard that you won something today,” Brin said.

Up on the large screen behind them appeared a picture of Al Gore, who on this day had won the Nobel Peace Prize for his work on behalf of the environment, an award that was featured in the morning papers and dominated the news.

“We all feel grateful to you,” Brin said.

“Thank you, Sergey. And to you and Larry and Eric and the entire team. One of the fun things in my life is to be part of the extended Google family.”

A roar of applause cascaded from the balcony and throughout the cafe, and soon Gore was gone.

“He sounded a little like Stephen Hawking,” joked Page.

The hand of an engineer who spends too many hours in front of a computer screen shot up. “Larry and Sergey,” he asked. “Which prize?”

The personalities of the founders permeate the company. Doerr described Sergey as the “more exhuberant” of the two. “Sergey is more creative, more experimental than Larry is.” One longtime Google executive decribes him as a ham. “I love Sergey,” the executive adds. “He’s an exhibitionist. He needs more attention than Larry does.” Brin does most of the talking, and joking, at Friday TGIF gatherings. In the early days of Google, when they took the entire staff camping for a weekend, everyone had a canoe partner, except Brin. “He said, ‘It doesn’t matter. I’ll swim.’” Wearing a lime-green Speedo swimsuit, he jumped into the lake, becoming the center of attention. One cannot imagine Larry Page agreeing to appear on the game show To Tell the Truth, as Brin did in March 2001. The question posed was “Who is the real Google guru?” Each of the three contestants wore a Google T-shirt, and after questioning them, the four celebrity panelists unanimously guessed that the real guru was panelist number 3, who turned out to be a professional bowler. Only 22 percent of the audience guessed that Brin was the guru. But when it came time to stand and identify the real guru, Brin histrionically pretended to stand, then sat, then rose to shocked audience applause, reciprocating with a slight but delighted smile.

Despite the playfulness, few would describe the founders as ideal mediators. They are often too brusque and intimidating for that role. “Larry can be a little raw, but never unkind,” said Megan Smith, vice president of new business development. A part of the rawness is due to the fact that they are geeks, more comfortable staring at a computer screen than schmoozing, and too zealously impatient to waste time.

Page is more reclusive, and odder. He was once asked at a dinner, according to a dinner guest, “What’s the most important thing the government should be doing?”

“Colonize Mars!” Page said.

Most of the dinner guests nodded as if he had said something profound.

Page can be almost monklike. He ruthlessly guards his time, and can treat those who ask him to make a speech or meet reporters as if they were thieves trying to steal his time. A longtime Google employee describes Page this way: “Larry is like a wall. He analyzes everything. He asks, ‘Is this the most efficient way to do this?’ You’re always on trial with Larry. He always pushes you.”

While Brin is more approachable than Page, he, too, can be awkward around strangers. His wife Anne Wojcicki’s company, 23andMe, was feted at a fashionable cocktail party in September 2008 that was cohosted by Diane von Furstenberg and her husband, Barry Diller, Wendi and Rupert Murdoch, and Georgina Chapman and her husband, Harvey Weinstein. The event was held at Diller’s Frank Gehry-designed IAC headquarters in Manhattan. Brin appeared wearing a dark crewneck sweater and gray Crocs. He and Google are investors in her company and he is openly proud of her work. But she had to quietly beseech him to stay. He did, but hid behind his oversized Canon camera, moving about the vast room or retreating to a corner, always snapping pictures.

THE YEAR 2000 BEGAN with two bangs. The first was that Google entered the new year averaging seven million searches a day, a massive jump from half a million at the beginning of 1999. The second was the sudden crash of technology stocks. Between March and October, the NASDAQ Composite Index, which lists most tech and Internet companies, fell 78 percent. Yahoo’s stock at one point plunged from $119 a share to $4. As a private company, Google was both spared and offered opportunities. “As in any successful venture, there’s a lot of luck,” said Hal Varian. “One of the great things from Google’s point of view was the dot-com collapse in 2000. A lot of talent became available.” Google cherry-picked some good engineers.

But the company was burning through its cash. While Google’s revenues would total $19.1 million in 2000, its losses would be $14.7 million, more than double those of the previous year. And they’d had “zero discussion” about any kind of Google advertising until late 1999, recalled Salar Kamangar, who crafted Google’s first business plan and became vice president of product management. The founders feared ads would slow searches. They still believed Google could outsource monetization to ad firms like DoubleClick, or sell their search services to corporations. Page and Brin were relying on their faith that a way would be found to make money. This faith produced more friction with their two major investors, but Page and Brin were undeterred.

In The Search, John Battelle describes an encounter around this time between Page and Brin and Bill Gross, the founder of the Go To search engine. Gross had come up with an idea: he was convinced advertisers or Web sites would pay more for certain keywords if they could pay on a cost-per-click (CPC) basis, meaning they paid only if the user showed enough interest in a given ad to click on their link and perhaps make a purchase. The price for the keyword and the placement of the ad would be set in an online auction process. By mid-1999, GoTo had a network of eight thousand advertisers, with some paying by the click and others paying a fee to appear at the top of the search results. Gross approached Page and Brin to propose that the two companies merge, reports Battelle, but “Brin and Page turned a cold shoulder to Gross’s overture. The reason given: Google would never be associated with… a company that mixed paid advertising with organic results.” (Gross later changed his company’s name, GoTo, to Overture, and in 2002 would sue Google for allegedly stealing its cost-per-click model.)

Meanwhile, Google decided to offer its search to other Web sites and to share any revenues. It was a way to extend its reach, and to be paid for the use of its search engine. The most significant deal, signed in June 2000, established Google as Yahoo’s official search engine. Google paid dearly for the privilege, granting Yahoo a warrant to acquire 3.7 million shares of Google when it was issued. And few users knew they were conducting a Google search, because Yahoo wouldn’t allow Google’s branded search box on its page. For Google, the deal was another milestone. Its search traffic doubled to fourteen million on the first day of the partnership.

While most experts by the end of 2000 thought Google had the best search engine, this claim was conjectural. What was indisputable was that Google was now the most-visited search engine on the Web, with one hundred million daily search queries and a worldwide market share of about 40 percent. Yahoo had given Google a boost, but “it was really about the quality of the search,” said Search Engine Land editor Danny Sullivan. “People were coming to Google because they heard about it.” The rapid growth would provide Google a vital and at the time overlooked asset. More searches generated more data for Google about users, which led to better searches, which would eventually lead to more ad dollars.

The question of how to monetize search by turning traffic and data into cash remained unanswered. Unlike AOL, Google didn’t have subscription revenues. And unlike portals such as Yahoo, it didn’t have content sites on which to place banner or display advertising. In October 2000, Google introduced its first advertising program, called AdWords. It was a small beta test, available to 350 advertisers who paid for a selection of search keywords that allowed the advertiser’s small text ads to appear on the side of the search results. It was a self-service program. Companies gave Google their keywords and went online to retrieve data on the number of times users typed their keywords into the search box. The effort was clunky, and grew very slowly.