About 200 investors showed up to an IPO presentation in Palo Alto, California, where they were given the opportunity to quiz Zuckerberg and his lieutenants. Wall Street had been concerned about the company's ability to wring revenue from mobile users, considered crucial for long-term growth.
Zuckerberg and Sheryl Sandberg, Facebook's chief operating officer, said the company's overall advertising business was gaining steam, with most marketers increasing their spending with Facebook.
The two executives, who appeared on stage alongside finance chief David Ebersman, highlighted social ads as an important tool for Facebook to tackle its mobile challenge.
Facebook aims to raise about $10.6 billion via its initial public offering, dwarfing the coming-out parties of tech companies like Google Inc and granting it a market value of up to $96 billion - rivaling Amazon.com Inc's . On Thursday, a source close to the process told Reuters its IPO was already oversubscribed, a week before final pricing.
The offering marks a watershed moment for the new generation of Web companies that are challenging established players such as Google and Yahoo for consumers' online time and for advertising dollars.
With 900 million users, Facebook is the world's dominant social network. Mark Zuckerberg, the company's co-founder and 27-year-old CEO was Time Magazine's Person of the Year in 2010 and was depicted in the fictionalized 2010 movie The Social Network.
"It is a bit of a celebrity event," said Alice Evans, with London-based F & C Asset Management. "You're not expecting to learn that much but its as close as you can get to kicking the tires."