The company has been busily collecting that data for seven years, compiling the information that its more than 800 million users freely share about themselves and their desires.
Facebook's value will be determined by whether it can leverage this commodity to attract advertisers, and how deftly the company can handle privacy concerns raised by its users and government regulators worldwide.
As the biggest offering of a social networking company, the sale is the clearest evidence yet that investors believe there is a lot of money to be made from the social Web. Facebook's dominance in this field has left Google, a Web king from an earlier era -- less than a decade ago -- racing to catch up.
Facebook is considered so valuable because it is more than the sum of its users. More than the world's largest social network, it is a fast-churning data machine that captures and processes every click and interaction on its platform.
Every time a person shares a link, listens to a song, clicks on one of Facebook's ubiquitous "like" buttons, or changes a relationship status to "engaged," a morsel of data is added to Facebook's vast library. It is a siren to advertisers hoping to leverage that information to match their ads with the right audience.
Barring an unforeseen event, the Internet giant plans to list a preliminary fund-raising goal of $5 billion, according to people briefed on the matter, smaller than some previous estimates of the offering. But it is essentially a placeholder, a starting point used by companies to generate interest among potential investors.
The eventual offering is expected to be the largest for an Internet company, bigger than Google's in 2004 or Netscape's nearly a decade before that. Trading of the stock is expected to begin by late May, the people briefed on the matter said.