By Melony Roy

MENLO PARK, Calif. (CBS) —  Facebook continued its reign during 2013 at the biggest social network in the world, but not without some hiccups.

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The site started the year with a big announcement from founder Mark Zuckerberg:

“Today, we’re finally going to talk about that Facebook phone.”

Long anticipated, it was but not part of most conversations by year’s end.

Facebook also added Twitter-style hashtags, graph search, and chat heads.

There was some debate about whether Facebook had a teen problem when its CFO admitted during an earnings call that daily use among some teens may be declining.

But what was popular with teen this year is the Facebook-owned photo sharing app Instagram, which hit some major milestones in 2013.

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First, Instagram tried to cut Twitter’s Vine, with an announcement from Instagram founder Kevin Systrom:

“I’d like to introduce video on Instagram.”

The network also posted its first advertisements, and after parent company Facebook’s billion-dollar offer to the rapidly growing messaging service Snapchat, Instagram then debuted its own private messaging feature.

(Systrom:)   “Today I’d like to introduce Instagram Direct, a simple way to send photos and videos to your friends.”

Instagram has over 150 million users sharing more than 55 million pictures every day.

Facebook — under the microscope on Wall Street to develop more revenue — will end the year on a high note with the recent launch of video ads.  The stock has risen from the ashes and joined the S&P in December.

More 2013 Year in Review stories

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