The chatter surrounding the robust marketing opportunities inherent to social networks is as old as the news of Facebook signing up its 100-millionth subscriber. However, social communities like Facebook and Twitter—which boast 750 million and 200 million users, respectively—keep growing at break-neck speeds, and brands are continuously finding new ways to engage audiences via these platforms. Kids TV properties are certainly no different. In fact, over the course of the past few months, a crop of family-friendly TV shows have launched unprecedented social media campaigns on Facebook and Twitter in an effort to build brand awareness, broaden their demographic reach and introduce new methods of content delivery.

In July, Nickelodeon US debuted the first-ever original SpongeBob SquarePants storyline created exclusively for Twitter in an effort to engage the roughly one-third of SpongeBob fans who are teenagers and adults. The episode, “The Ice Race Cometh: A Twitter-Tale,” was developed for Twitter and Facebook by the SpongeBob writing team and allowed users to watch, and engage in, a dialog between the series’ characters. The story unfolded via a series of multiple messages and images posted on Twitter and Facebook between July 12 and July 15, and was designed to serve as a prequel to a new full SpongeBob episode called “Frozen Face Off” that aired on July 15.

“With anything that we do, the digital rule is to expand the brand and give audiences new ways to engage,” says Steve Youngwood, EVP and GM of digital at Nickelodeon Kids & Family Group, adding that the SpongeBob brand is perfect for experimental Twitter marketing due to its cross-generational appeal. And in this case, the show’s writing team and in-house digital staff were on-hand to deliver the content, meaning there were relatively no additional marketing costs. The brand’s Facebook page, meanwhile, boasts 26 million fans—that’s more than US President Barack Obama.

“Our goal is to service audiences on various platforms who are already there; it’s not to drive people to the platform itself. Those 26 million Facebook fans aren’t on Facebook because of SpongeBob, but we’ll certainly entertain them since they are there,” says Youngwood.

For the under-13 set who are prohibited from registering on Facebook (even though we know at least 7.5 million have done so anyway), official website Spongebob.com offers kid-friendly games and content. Still, Youngwood insists that while platforms like Twitter and Facebook may be for mature users, the content disseminated through these networks always respects the kid-friendly editorial voice of the series.

In terms of bolstering fan engagement, which Youngwood contends was the purpose of the initiative, SpongeBob’s Twitter fan base grew by 20% over the course of the campaign. “The hope is to turn fans into brand and TV-viewing fans,” he says.

Also tapping into an existing social media fan base is BBC Worldwide through its top-selling family-friendly series, Doctor Who. The BBC’s commercial arm has recently placed a series of digitally re-mastered Doctor Who episodes for rent for 48-hour periods on Facebook. Using Facebook credits, fans are able to stream a selection of nine stories from the science fiction series, including never-before-seen content.

“We decided to give fans a taste of the best episodes of Doctor Who‘s past,” says Fiona Eastwood, commercial director for Doctor Who at BBC Worldwide. Eastwood says the Doctor Who Facebook devotees—which count 1.2 million since the page’s December 2010 launch—were asking for access to content via the social network. “There’s a two-way conversation on Facebook, and with new content we see comments and responses that number into the hundreds. Plus, we can see what fans like from video content to merchandise, which can inform future product development and live event ideas.”

While roughly 30% of Doctor Who‘s audience in the UK and Australia is comprised of eight- to 12-year-olds, the Facebook initiative is technically targeted at fans ages 13 and older. But such enhanced marketing efforts built around family and kid-friendly content on adult-driven social networks seems like a controversial trend. Whether it’s intentional or not, is this type of marketing actively encouraging young kids to venture onto networks where, at least in the case of Facebook, their presence is actually prohibited? Are they being subjected to adult content and advertising that they shouldn’t see?

Stacey Matthias, founder of New York-based research and strategy firm Insight Kids, believes that social media can be a powerful tool for young kids and adolescents, as long as the content allows them to appropriately express who they are.

“Good social media content may create brand awareness and drive affinity, but it also has to help kids do the work of growing up. That’s the only way to play responsibly in this business,” she says.

Since kids use all media to explore new ideas, simple gestures like posting a line of dialog from a TV show on Facebook or tweeting about a new episode can be used to express their social behavior and indicate that they are immersed in popular culture. The content and conversations occurring on networks like Facebook are very alluring to kids ages nine to 13, says Matthias.

“In some ways Facebook is a manifestation of what they are doing in their own lives, which is maintaining connections and presenting themselves to others. If you think about it, middle school is like Facebook on steroids.” And since they are there anyway—official registration rules or not—Matthias says content creators and marketers need to keep in mind how their messages are being delivered and processed by the youngest of users.

Those points seem particularly important when it comes to creating and marketing an entirely new kids property in the social media space. Turner EMEA’s first European-produced toon, The Amazing World of Gumball, which is set to debut this month on Cartoon Network UK, has been introduced to the masses through a full-scale digital promotion. For instance, the broadcaster has ordered a total of 28 videos that will be posted on a YouTube channel called Elmore Stream, named after the show’s fictional hometown. Also forming a part of the social media campaign is a Facebook page housing clips, quizzes, questions, quotes and a host of show information. Both the YouTube and Facebook activity will be maintained in eight territories across EMEA in 15 languages and managed by London-based creative agency Holler.

“This is a first for us, and we have big ambitions behind it,” says Louise Okafor, director of digital entertainment at Turner Broadcasting UK. “We have access to show creators and bespoke social content in order to make the biggest splash and reach the biggest audience possible.”

Okafor says that the technological themes of the show and its cross-generational appeal lend themselves to use in the social media space, and therefore this strategy was built into the show’s framework and budget from day one. “We know we have kids already accessing 17 Cartoon Network websites across Europe, but we felt with this appeal we could reach new audiences who don’t ordinarily come to our sites,” she says.

Similar to the case of Nickelodeon’s SpongeBob campaign, Gumball‘s show creators brainstormed with an in-house content team to make characters exist in different social spaces. The series’ father figure, for instance, has his own Twitter feed where he delivers posts and uploads photos. “Twitter is one niche audience, but it is filled with opinion-makers and lots of people from the animation community,” notes Okafor.

The campaign’s Facebook promotion, meanwhile, has helped garner 90,000 fans since launching in May. Whether or not those fans turn into viewers remains untold for now. Okafor says the social media strategy will extend until the end of the year, after which time an extensive review will take place.