"Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in my life," Zuckerberg wrote in a on Facebook. "I am committed to working every day to make Facebook better for you, and hopefully together one day we will be able to connect the rest of the world too."

Easily the most popular social network in the world, Facebook said it has seen 140.3 billion friend connections, 219 billion photos uploaded, and 62.6 million songs played 22 billion times, adding up to about 210,000 years of music.

"This means that whatever problems its had or has, there's still a huge asset here and it's not going away," said Ezra Gottheil, an analyst at Technology Business Research.

"It was never the powerhouse people thought it was, and it was never the abject failure people thought it was. It's a young company with a magic formula for generating traffic. It has amazing tech, but its business model is still evolving, and it still makes beginner mistakes," Gottheil added.

Facebook's success has come amid a slew of obstacles.