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Analysts told CNBC this trend could get stronger this year, threatening to erode the social networking giant's dominance, although most said it would be hard to imagine a world where Facebook loses its crown completely.

"There is a real risk of social media fatigue, as evident from the fall in overall usage of social networking sites like Facebook and Twitter by average folks, and this is why leading companies like Facebook need to be forward looking in order to stay relevant," Sanjeev Kumar, at business management firm Delamore Consulting told CNBC.

At the end of 2013 researchers at digital consumer data provider GlobalWebIndex found that the number of U.S. teenagers active on Facebook fell to 56 percent in the third quarter of 2013 from 76 percent in the first quarter. The firm defines active usage as the number of users that have used or contributed to Facebook in the past month on any device.

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The rise of messaging apps

According to GlobalWebIndex, these disinterested teenagers are turning to messaging apps instead, with messaging app WeChat, video blogging site Vine and photo sharing site Flickr seeing the largest surges in popularity respectively.

When CNBC contacted Facebook the company disputed that it was losing popularity with its teenage user base.

"Overall teen usage has remained stable, and teens are among the most active users of Facebook. We remain focused on overall user engagement, including teens," a spokesperson for Facebook said.

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"Teens remain the most active users of Facebook and its clear they use multiple platforms but Facebook remains a leader in a growing space," they added.

Continued here:
A world without Facebook: Will it happen?