Earnings Preview: Facebook posts 3Q results Tues.

NEW YORK (AP) — Facebook Inc. will report its third-quarter earnings results — the second as a public company — on Tuesday after the stock market closes. With its stock trading at roughly half of its initial public offering price, the online social networking company has been working to grow its advertising revenue without alienating its 1 billion users.

WHAT TO WATCH FOR: Online advertising rival Google Inc.'s disappointing results, announced prematurely last Thursday, dragged Facebook's stock lower too. Google's ad revenue grew at the slowest pace in three years in the July-September quarter, which some investors took as a sign that Facebook could see a slowdown too.

Susquehanna analyst Herman Leung thinks a big area of focus will be Facebook's progress in mobile advertising. Facebook only recently started showing ads, which it calls "sponsored stories," on mobile devices. The challenge with small screens is showing the ads without annoying users.

The company has launched several new products and features recently that could boost revenue growth. These include the Facebook Exchange, which lets advertisers target users in real-time, based on outside websites they visit. So if you visit a store's website, you might see ads from them on Facebook. A gifts feature, meanwhile, lets users buy physical gifts for their friends through their Facebook account. Investors will be looking for updates on how these and other new features have fared.

Leung said he'll also be listening for an update on new ways for advertisers to measure how well their ads are working on Facebook. He has a "Positive" rating on Facebook and a target price of $32.

Sterne Agee analyst Arvind Bhatia, meanwhile, notes that looming expirations of post-IPO lockup periods could weigh on Facebook's stock as employees start selling their shares.

"That said, we think the sentiment on the stock is already quite negative and we believe the long-term opportunity for (Facebook) remains very large," he added. He kept a "Buy" rating and $26 price target.

WHY IT MATTERS: Facebook is the dominant social networking company in the world, with more than 1 billion users. Its results are a gauge of the health of social media companies, as well as the overall online advertising environment.

WHAT'S EXPECTED: Analysts, on average, are expecting earnings of 11 cents per share on revenue of $1.23 billion, according to FactSet. Facebook has not given an outlook.

LAST YEAR'S QUARTER: Facebook was still a private company. It had net income of $227 million and revenue of $954 million in the third quarter of 2011.