Facebook is undoubtedly the media phenomenon of the 21st century and advertisers are working hard to keep up with and respond to the ever-changing behavior of young people who dominate the site. What do these influential teens and twenty-somethings think of big brands’ recent arrival on their turf? Nick Mawditt of Kinetic has spent a great deal of time with them. This is what he’s learned.

How much budget are the most pioneering firms allocating to social media? According to a new survey of corporate communications and marketing specialists, anywhere from 5-15% of the “overall external communications budgets” is being earmarked for social. It’s better than the sums we saw just two years ago, but how exactly is that supposed to cover costs on a year-round “holistic” communications strategy?

Sony Ericsson launched a new Facebook giveaway contest last week to celebrate its Xperia X10 mini phone launch enticing fans to compete for a freeby handset. The numbers suggest giving away free stuff is still a tried and true way to get fans to rally around your brand. Go figya.

It goes by a few different names: “branded content,” “branded publishing,” and, more recently, “social media branded content.” What is it? It’s company-produced content – not just blog posts and Twitter updates, but long-form narratives, games, video and crowdsourced initiatives, to name a few – that pulls in the public. New studies say it could be the biggest marketing and corporate communications trend of 2011.

We’ve entered the month of the great holiday season, and more apps are coming out for your social shopping convenience. We review the best (and the worst) so you can make the most of your Christmas ham.

Nearly two months after its debut, Twitter’s “Promoted Account” marketing scheme has provided companies with newer ways of upping their follower numbers. But is investing in a place on the “Suggestions for you” listing worth it? We look at three brands who’ve taken the early plunge. If time has taught us anything about this new program it’s that money can’t buy you followers.

Thanksgiving may be over, but the real fuss is just beginning. It looks like Christmas 2010 will go down as the first truly social media Christmas. How are big-name retailers using social media to beat out competitors today, Black Friday? We take a peek and give out the grades.

A recent study sponsored by the Social Media Success Summit suggested that 88% of businesses were using social media networks for marketing with the most commonly used platforms being Twitter, LinkedIn and Facebook.

Don’t mess with It Girls. We’re talking of course about the massively popular Facebook game that now counts close to 5.5 million style-savvy gamers. The aim of It Girl is to build a confidence-boosting virtual wardrobe that leads inevitably to a state of unquestioned “Hotness.” This holiday season, via a novel real-meets-virtual alliance, It Girl gamers can add Old Navy duds to their wardrobe.

Fortune 500 companies are showing off their social acumen with more regularity, in particular, increasing their blogging and Twitter activity in 2009, a new study out this week says. But there are no gold stars for this sector. The Fortune 500 still lags behind the younger, faster growing Inc. 500 in terms of social media uptake.