Facebook, the vast online social network, is poised to file for a public stock offering that will ultimately value the company at $US75 billion to $US100 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. Anticipation over Facebook Inc.'s pending initial public offering has fueled a recent surge in stock prices of social media companies in China, where Facebook is blocked.