The two biggest stories in digital right now are Facebook… and Facebook. On the eve of an IPO that could value Facebook at $100 billion we get word that automotive giant General Motors is pulling its $10 million Facebook ad budget on account of diminished returns. Is GM telling us something, that Facebook is a waste of money as a marketing opportunity? The answer: not so fast.

Engagement is the new currency for social marketing effectiveness, particularly for brands who are seeing renewed life on their Facebook fan pages ever since the new Timeline was introduced earlier this year. A new study out this week looks at which industry sectors are getting the most mileage (there’s one hint) out of their social engagement strategy.

We’ve written a few times here about Ford’s for-the-people approach to marketing its new models, an approach that relies heavy on social. As a kind of follow-up we have an interesting piece of research from social metrics specialists Inefegy that looked at how Ford weathered a recall storm a few weeks back. Hint: there’s a silver lining in here for save-the-world eco-types.

This year’s Super Bowl saw five times as much social activity as last year, figures from Trendrr suggest, which is not surprising given research by Coco-Cola showing that at least 60 percent of viewers were expected to have a smart phone, tablet or computer within arm’s reach and that an average of 10,000 Tweets per minute were fired off in game’s final three minutes.

One year ago, we published the inaugural Social Media Sustainability Index, a trawl through 287 major companies in North America and Europe to identify who was using social media tools and thinking to communicate sustainability. …

…it goes to the NHL’s Detroit Red Wings, the Motor City’s perennial ice hockey power who tried to whip up a bit of fan excitement in early April for their eventual failed Stanley Cup run this year with a car give-away. What’s not to like there?

Aunt Jemima, arguably America’s oldest and most recognizable pancake brand, has proved that you can teach an old dog new tricks. With the help of PR powerhouse Weber Shandwick, the brand launched its official social media presence two weeks ago in conjunction with a simple yet effective social undertaking.

Ford, along with Montana-based sports marketing and comms specialists Outside Media, launched a Facebook campaign earlier this month that lets users compete for a sponsored adventure in the new Ford Explorer 2011. While the campaign tactics itself are far from revolutionary, Ford continues to distance itself from the rest of the SUV pack, building the Explorer into the social brand of choice. Here’s the breakdown.

Well, it’s Facebook official. Mattel, the iconic toy company, has reunited its most famous couple in a monthlong social media campaign just in time for Valentine’s Day. Was the boost in romance enough to goose Facebook fans, too? Here are the results.

Do you recall back in 2006 when eco activists hijacked General Motors’ big Chevy Tahoe online marketing blitz, using the campaign to post their grievances with the automaker’s environmental track record prominently on its own web site? We didn’t know it then, but this savvy counter-attack kick-started the social media activist movement. It’s also motivated companies to better communicate their CSR accomplishments with the public. How are they doing? We tell you here.