Open... and Shut In May 2012 Facebook is set to launch one of the top-25 IPOs in history. By May 2013 it may well be scrambling to keep investors happy, given the apparent flight of teenagers to Twitter, Pinterest, and flavor-of-the-month social media. It's not that Facebook has lost its mojo. It's that it may be becoming cool with the wrong sort of people: parents.

I live in a pretty close-knit neighborhood where church, sports, and other activities tie neighbors together. As such, I've been "friends" on Facebook with many of my kids' real-world friends. A few months ago, however, I noticed something: they weren't posting to Facebook as frequently. I didn't really know what was happening until one posted: "Facebook has become the Wal-Mart of social: I'm heading to Twitter."

He wasn't alone. Yesterday I checked and discovered that all those teenage "friends" are now happily posting on Twitter. And it's not just my neighborhood, either.

According to Pew Internet Research, Twitter adoption among teens has doubled since September 2009:

Facebook adoption is much bigger, of course, but Twitter is the growth king. Demographic studies of other social media services, like Google+, Instagram, and Pinterest, are also seeing an uptick in teen adoption.

In part, this is a classic youth revolt against The Man. GrownupThinking.com surveyed 2,000 teenagers and found that many of Facebook's recent changes (such as the ticker) are turning off teens, sending them to rival services.

Twitter's open source guru, Chris Aniszczyk, suggests one reason teenagers may feel that Twitter offers them better privacy controls:

@mjasay no real names are technically required... just handles... — Chris Aniszczyk (@cra) April 9, 2012

True, but in my limited dataset, all of the teens are using their real names. And while it's true that these teens could close off their accounts so that only their peers can see their tweets, none of them appear to be doing this. At any rate, this same functionality is available on Facebook.

Rather, Twitter seems to be a cleaner evolution of texting, except with broader groups of friends. And because the parent crowd doesn't seem to be on it yet - at least, not in the same way as has happened with Facebook - teens feel like they have more privacy, even though their tweets are more public than their Facebook activity ever was.

Not that this will disturb Facebook too much today. The company is a great job of bringing in new users across the globe, and so isn't dependent on fickle Western youth.

But it does need to worry about the youth vote, as it were. Some stock analysts suggest that Facebook's aging population is a great thing for its business, arguing: "An older Facebook demographic means that the Facebook experience will change inevitably to accommodate an audience with deep pockets, one that is less interested in connecting, or liking, or [be]friending, than in consuming content and completing transactions."

Perhaps. Or it could also signal a shift toward cooler pastures, just as teenagers falling out with MySpace indicated that end of the line for its business.

But there are other causes for concern.

One major one could be advertising revenue, the heart of Facebook's business. By TBG Digital estimates Twitter is killing Facebook in terms of Cost per Impression (CPM) metrics. In this analysis of 45 billion ad impressions, Facebook nabbed less than $0.50 per impression while Twitter pulled in more than $3.50. Granted, Twitter served far fewer impressions, but the statistic isn't a positive one for Facebook.

Add this to Facebook's decelerating daily user growth, and you have a recipe for concern, though not yet disaster.

As the youth flee Facebook for the relative obscurity of Twitter, and investors start to chafe at the warts in Facebook's business model, Twitter may start to look like a comparatively cheap bet compared to Facebook's $100bn valuation. Twitter, for its part, needs to figure out how to get even more teenage tweeters and take advantage of its new status as the place where the cool kids hang out.

That and figure out a hedge against teens' eventual quest for something new, post-Twitter. ®

Matt Asay is senior vice president of business development at Nodeable, offering systems management for managing and analysing cloud-based data. He was formerly SVP of biz dev at HTML5 start-up Strobe and chief operating officer of Ubuntu commercial operation Canonical. With more than a decade spent in open source, Asay served as Alfresco's general manager for the Americas and vice president of business development, and he helped put Novell on its open source track. Asay is an emeritus board member of the Open Source Initiative (OSI). His column, Open...and Shut, appears three times a week on The Register.