Facebook Milestones Leading to a Billion Users in a Single Day

Facebook is celebrating one billion daily active users for the first time ever.

ByABC News

August 28, 2015, 11:47 AM

Founder of Facebook Mark Zuckerberg, right, and Dustin Moscovitz, co-founder have their photo taken at Harvard Yard in 2004 in Cambridge, Mass.
Justine Hunt/The Boston Globe/Getty Images

 -- When Mark Zuckerberg launched Facebook from his Harvard dorm room in 2004, his audience was college students.

Eleven years later, the Facebook CEO celebrated a milestone: One billion people -- that's 1 in 7 people on Earth -- logged onto the site in a single day this week.

"When we talk about our financials, we use average numbers, but this is different. This was the first time we reached this milestone, and it's just the beginning of connecting the whole world," Zuckerberg wrote in a Facebook post on Thursday. He said the record moment happened on Monday.

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Starting out with an ambitious vision, even Zuckerberg didn't foresee the force Facebook would become in connecting the world.

"People often ask if I always knew that Facebook would become what it is today. No way," he reflected on Facebook's 10th anniversary on Feb. 4, 2014. "I remember getting pizza with my friends one night in college shortly after opening Facebook. I told them I was excited to help connect our school community, but one day someone needed to connect the whole world."

And he was the one who did. Here's a look at some of the key moments and milestones that helped Facebook build its user base.

2004: The site was intended as a directory of Harvard students only, but within months, thousands of students from elite colleges across the country had joined the network.

2004 -- original page (we've got this from FB)

2006: Open registration launches, letting anyone who wants to make a profile join the social network. The newsfeed feature also launched this year, letting people stay more engaged to their friends' updates -- and kept them coming back for more.

Facebook Inc.'s mobile application is demonstrated on an Apple Inc. iPhone at Facebook's headquarters in Palo Alto, Calif. Sept. 8, 2009.

2008: The Facebook app makes its debut, giving users even quicker access to checking in on their friends' updates.

2012: Facebook goes public with a $5 billion IPO.

2015: Facebook continues to innovate with new ways for people to engage with the world. Among them are video calling in the Messenger app, easy-to-read instant articles and a live-streaming feature giving users a front row seat to the latest happenings from their favorite celebrities and news makers.