Facebook, the vast online social network, is poised to file for a public stock offering on Wednesday that will ultimately value the company at $75 billion to $100 billion, cashing in on the fuel that powers the engine of Internet commerce: personal data.

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.