Facebook’s IPO is the biggest thing to hit the stock market this week (this decade, really). The company name has been filling the headlines with speculation regarding their IPO offering, a billion-dollar figure, and the expectations behind its entry on the Fortune 500 shortlist.

Facebook’s business model has also attracted lots of attention with the pending IPO, particularly how they’ll develop around advertising, building out their monetization efforts for their burgeoning mobile brand and other media entities.

Here’s your final roundup of Facebook news before the IPO hits:

Facebook tops social on Android – needs to leverage mobile presence

According to new SmartMeter data, the NPD Group’s Connected Intelligence sector, Facebook’s app and social site is the most used social networking website and app on the Android platform. Nearly 75 percent of U.S. Android smartphone users have accessed the platform in March, making it the most popular social-networking site on the Google platform.

The Facebook app on Android  has quite a reach, with users spending over 15 minutes a day, or almost 470 minutes a month.

In its regulatory filings leading up to its IPO Facebook said that usage growth is a result of their innovative mobile products. The company hasn’t yet publicized details on how they plan to monetize the 500 million users who use Facebook on their mobile devices. The current data will benefit the company in unleashing their mobile advertising potential, a necessity for Facebook once they go public.

“Ultimately, Facebook’s mobile success rests on delivering compelling mobile app and web experiences, and monetizing on these experiences,” said Linda Barrabee, research director, NPD Connected Intelligence. “In order to do this, Facebook needs to ensure that monetization efforts via advertising enhance and do not disrupt the mobile social consumer experience; and with Facebook’s IPO looming and trading expected to begin on May 18, all eyes are on the company.”

Facebook Pages Manager app debuts for iOS

During the build-up to Facebook’s $100 billion-plus IPO offering, mobile took center stage. Yesterday, the social network giant quietly unveiled Facebook Pages Manager, an app for iOS for marketers and advertisers to manage their brand pages.

The app looks similar to the current Facebook iPhone app, and allows users to view recent user activity, writes post, and access Page Insights stats, like the number of people visiting your page, the weekly total reach and number of people talking about your profile pages.

“We’re testing an app that helps owners of small to medium Pages more easily manage their Facebook presence,” Facebook said in a statement.

The free app is available for download via the iTunes store in selected regions only. Facebook didn’t say whether the Android app will get a similar app offering.

Facebook’s One Trillion Dream

Could any company ever top the trillion-dollar mark beating established giants like Apple, Exxon Mobil and Walmart? An interesting analysis on Mashable thinks Facebook has that potential.  And surprisingly, it could be sooner than you think.

According to the social network’s latest S-1 securities filing, advertising accounted for more than 80 percent of its $1billion in revenue in the most recent quarter. The company had revenue of $3.7 billion last year.  After the IPO, the company will be valued 27 times of that revenue at around $100 billion.

So theoretically, if the permutations and combinations are correct, another $37 billion in revenue or over 120 percent annual revenue growth year after year will lead Facebook to reach the trillion dollar mark. At this rate, the company will hit $37 billion at some point in 2014.

The most likely source of this growth would be advertising. Facebook is also expanding outside of its traditional product lines, most notably into mobile business.

“You don’t have the distribution problem, you don’t have the manufacturing problems, you don’t have problems that typically limit growth,” says technology analyst and Enderle Group president Rob Enderle. “Facebook’s limits are simply the speed at which it can grasp a particular group.”

But does Facebook will ever reach that milestone? Enderle predicts “That would be a textbook mistake.”

Facebook monthly active user base has increased by 118 percent between March 2009 and March 2010, but it slipped to just 43 percent between 2010 and 2011 and further to 33 percent last year.

In addition, Facebook’s $100 billion valuation is due to the expectation of demand for stock, not because of its income. It had a lower advertising revenue figure last quarter compared to the previous quarter. Moreover, Facebook experienced a setback when General Motors pulled $10 million worth of ads from the platform.

“If Facebook were to focus on becoming a $1 trillion company, they probably won’t make it,” Enderle says. “You over-set expectations. If employees are led to believe it will be a $1 trillion company, and if investors are led to believe it will be a $1 trillion company, and if Facebook only triples itself, in the eyes of those people it will have failed.”

Mark Zuckerberg Returned to Writing Code

Bloomberg Businessweek’s story on how the Facebook founder hacked the world of Silicon Valley revealed the young entrepreneur is again going back to his roots – he has started writing code after a six-year hiatus from programming.

So what took Zuck back to basics? As Facebook nearing public and some of its best talent will even get richer, the technical CEO wants to stand out as an inspiration to the engineers in what they value most – writing codes and focused on building Facebook brand.