Facebook is large, but is it the 'Titanic' of social networks?

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Let there be light.

For the first time ever, the world has a clear picture of just how many people are using services provided by the three social media giants: Facebook, LinkedIn and Twitter.

Going by the metric of monthly active users, Facebook leads the pack, with 1.19 billion. LinkedIn and Twitter have 259 million and 232 million, respectively.

[Share monthly active user stat.]

It doesn't take a math wizard to notice that Facebook has far more monthly active users than Twitter and LinkedIn combined. Throw in Instagram's 150 million users, and Facebook's photo-sharing application could even contend on its own.

But in the grand scheme, does Facebook have what it takes to outlast the smaller social networks?

"I think Facebook's going to be around for a very long time, not because their current product can last the test of time but because they're unusually adept at evolving," said Gregory Galant, CEO of Muck Rack, a site connecting journalists and sources over social media. "People forget that when Facebook launched, it didn't have most of the features we know it for today, including newsfeed, photos and timeline."

Galant attributes Facebook's lack of stubbornness to its ongoing success.

"Just as the original product Facebook launched less than 10 years ago would be irrelevant today, the current Facebook product will be irrelevant in 10 years," Galant said. "Facebook's staying power is its ability to radically change itself."

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Facebook founder Mark Zuckerberg highlighted that focus in a 2009 note.

"Since its founding, one of the constants of Facebook is that it has continuously evolved to make it easier to share," Zuckerberg wrote.

And when it can't create, it buys.

"Just as Google today is much more than search largely due to sage acquisitions, including YouTube and DoubleClick, Facebook's Instagram acquisition shows a further hunger to be a multifaceted company around a coherent theme," Galant said.

Its number of users may not affect Facebook's longevity as much as its ability to change.

"The fact that the Titanic was large didn't help its situation," Galant said. "It needed to be able to change course faster. Facebook's shown it can quickly change course, which is unusual for a big company."

By CNBC's Eli Langer. Follow him on Twitter at @EliLanger.