Just shy of its tenth birthday, Facebook reported earnings Wednesday with strong revenue, cheering investors who had worried that the firm was starting to show its age.

The social network beat analyst expectations for the fourth quarter, reporting $2.585 billion in revenue — up 44 percent from the same period last year. Analysts had expected $2.35 billion. The company finished the year with $7.8 billion in revenue, up from $5 billion in 2012.

The company reported a fourth-quarter profit of $523 million, or 20 cents a share, up from $64 million, or 3 cents a share, a year earlier. Adjusted earnings of $780 million, or 31 cents a share, beat analysts estimates by 4 cents.

Facebook shares shot up more than 11 percent in after-hour trading after closing at $53.53 per share.

So, all in all, Facebook has a lot to be pleased about. Or, as chief executive Mark Zuckerberg said: “It was a great end to the year for Facebook."

Here are some of the key metrics to take away from the company’s report and earnings call.

Young user engagement: Facebook has faced some pointed questions from investors as evidence builds — both from studies and through anecdotes — that the company is losing traction among teenagers. That, in turn, has raised questions about whether the network has the lasting power it needs to be a good long-term investment.

Executives on the earnings call didn’t offer specifics about how young people are using the networks — in fact, the company said there was no new data to report. But Zuckerberg did say that all users are doing more on the site, citing an uptick in the number of likes the social network sees.

“We’re also seeing people engaging more,” he said. “These trends show that our strategies of improving our core experience is paying off.”

Facebook has admitted, in a previous earnings call, that it is seeing lower engagement among teens. On the other hand, it also publicly ridiculed a Princeton University study that predicted the social network would lose 80 percent of its users by 2015 — indicating the company isn’t that worried about it.

Chief Operating Officer Sheryl Sandburg did say that Facebook is seeing high demand for Facebook features that focus on real-time conversation — traditionally something that’s Twitter’s turf. If it can tap into that conversation, it may have a better chance reaching teens who use social media to communicate their ideas.

Mobile use: Worries that Facebook wasn’t particularly strong on mobile plagued the company ahead of its public debut in 2012. But the social media firm is still growing strong on the smaller screen, reporting that mobile daily users have increased 49 percent over the same period last year, to 556 million.

Mobile monthly active users have also shot up, though less dramatically, to 945 million users — an increase of 39 percent from the same period last year.

Zuckerberg also spoke at length about the company’s vision for mobile apps such as Facebook Messenger, which he says provide much-needed separate experiences for Facebook’s users.

Mobile advertising: Analysts were expecting a big increase in mobile advertising revenue, forecasting $1.1 billion generated by smartphone and tablet ads. The company beat those high expectations, reporting that mobile ads had actually generated $1.2 billion.

Considering that Facebook only started selling mobile ads in 2012, that’s no small feat. Mobile ads are also making up an increasing percentage of Facebook’s revenue — now 53 percent of the company’s total take.

On the earnings call, Sandberg said that mobile ads generated $8 million on Black Friday alone.

And what are the plans for mobile ads moving ahead?

“Our plan is to continue focusing on improving quality,” Zuckerberg said, adding that he believes this is the way to keep revenue headed in the right direction.

Video ads: If you think mobile ad revenue excites analysts, it’s got nothing on what they expect for video ads. Facebook is currently testing the feature — a product that’s expected to be a real money-maker for advertisers who want to put mini-commercials on the social network.

Sandberg didn’t have much to say about video ads, apart from saying that the company is also testing a small amount of auto-play ads.

Essentially, however, she had nothing but good news when reporting how Facebook’s advertising products are performing. She credited some of that success to the company’s efforts to streamline its products, adding that marketers now see an eight-fold return on ads in the News Feed.

Instagram: Facebook’s Instagram buy has been help up as a logical way to solve many of the problems that plague the company — it’s ideal for mobile devices, and tends to draw a younger set of users than Facebook at large. The picture-sharing service has also been integral to Facebook’s efforts to add videos, and video ads, to its social network.

Instagram’s growth continues to help its parent company: Its user base over the past year, said Chief Financial Officer David Ebersman on the call. He did not provide specific numbers, but Instagram boasts 150 million users on its own Web site.

Ebersman also said that it’s too early to tell how many ads should show up on Instagram.

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