When potential hires ask why they should join Facebook, Mr. Zuckerberg said, 'Tell them: because people will remember your name.'

The company has had its fair share of management gaffes. Late last year, Facebook came under public fire for redesigning its privacy controls in a way that caused users to make more of their account data public.

Privacy advocates rallied and Facebook rolled back some changes, but regulators in the U.S., Canada and Europe are still watchful. Last week, the company acknowledged that a 'small number of users' had received private messages intended for other members. Facebook executives regularly stress that they are committed to giving users tools to protect their privacy.

'Facebook is in the phase where some founders get themselves into trouble by being too sure of themselves, says Jeffrey Sonnenfeld, a professor at the Yale School of Management, who has advised a number of Silicon Valley founders. The company 'is at a crossroads where we have to see if Mark can build a team strong enough to challenge him,' he says.

Some of his admirers, such as former Facebook employee and venture capitalist Matt Cohler, say he is a natural leader with 'a clarity of purpose that is remarkable.'

Mr. Zuckerberg has passed up several opportunities to sell and make a killing. These include a $1 billion offer from Yahoo Inc. in 2006 and an overture from Microsoft Corp. that was worth a possible $8 billion or more, according to people familiar with the matter.

Mr. Zuckerberg declines to comment on the talks, beyond saying: 'It always sounds a lot more concrete than it actually is.'

A spokesman for Microsoft and a Yahoo spokeswoman declined to comment on the offers. In October 2007, Microsoft invested $240 million for a roughly 1.6% stake plus some exclusive ad rights.

By early 2008, Mr. Zuckerberg began to take steps to help prepare the company to go public. He expanded his management team, hiring Google executive Sheryl Sandberg as his No. 2 in March of that year. He sought new perspectives by inviting Netscape co-founder Marc Andreessen and Washington Post Co. Chairman Donald Graham to join his board. He kept voting control over their seats, however.

'The company is definitely set up in a way where myself and the other founders have a lot of control over it,' he says. Investors who signed on, he adds, 'understood that they fundamentally weren't going to be able to push us in a direction that we wouldn't want to go.'

Any IPO timing is squarely in Mr. Zuckerberg's hands. He owns more than a quarter of Facebook's stock and controls votes for three of five board seats, say people familiar with the matter. A Facebook spokesman declined to comment on the board structure or Mr. Zuckerberg's ownership.

There's little pressure from Facebook's existing shareholders-mostly venture capitalists who say they are pleased with its positive growth trend.

Facebook executives have discussed how revenues for 2010 could hit between $1.2 to $2 billion, say people familiar with the matter. In 2009, the company said it was generating positive cash flow-more than enough to pay its 1,200 employees and overhead.

Mindful, though, of the inevitability of an IPO, Mr. Zuckerberg has consulted with several Silicon Valley wise men. Over lunches and milkshakes with people like former Netscape CFO Peter Currie, Mr. Zuckerberg has gobbled up advice, entering thoughts into what he calls 'the list' on his BlackBerry-a long to-do list of items for the future.

To distract employees from the buzz of an IPO, he pressed them to focus on building a bigger company. He led a toga party to celebrate Facebook's 100-million-user mark. He bought a gong for the office, which employees bang when they launch new products.

In late 2007, he and the board changed the types of shares granted to employees, significantly lessening the pressure on the company to go public and giving him more control over the timing of such an event.

The switch, which the board agreed to, was to pay employees in restricted-stock units instead of options. Holders of RSUs generally can't become shareholders until the company goes public; options holders have more flexible exercise rights.

So the move allowed the company to stay under 500 shareholders, the point at which the Securities and Exchange Commission requires companies to disclose more financial information.

Mr. Zuckerberg says that skirting the 500-shareholders rule 'crossed our minds,' but that the decision was also good for employees because of technicalities that made it cheaper for them to acquire their shares.

The ranks, though, were still anxious for a payday. Some began to seek private buyers of their shares, complicating the company's internal valuation for employee stock options. liuxuepaper.com

Their moves aggravated Mr. Zuckerberg, who often bragged to employees that he had a special capacity for delayed gratification, according to people he spoke with. He hammered home this idea to his management team at an offsite meeting, recounting a story about how he was good at waiting for things as a teenager.