A recent campaign by Nails Magazine illustrates the power of Pinterest as a visual marketing tool. Focused on creative designs for nails, the magazine also runs a Nail Art Gallery site – a forum for nail technicians and salon owners to share nail designs and receive feedback in the form of viewer likes, comments, shares and pins. The brand made a first foray onto Pinterest to help generate traffic, and saw huge results in terms of pageviews and Pinterest followers.

Cape Town Tourism placed a clever spin on the Facebook game – and contest – with the MyCapeTownHoliday.com competition, launched back in September 2012. The campaign invited people to ‘send their Facebook profile on holiday’ at Cape Town, and thousands chose to play by using an innovative Facebook app, cited by Cape Town Tourism as a “world’s first.”

The Intuit marketing team recently proved the power of social media in a campaign that combined mobile training and a social contest. Intuit – a global provider of financial software – is active on social media, and began this campaign looking to grow its Facebook audience and improve the brand’s online reputation.

Social media was the driving force behind Krispy Kreme’s launch in India this past Saturday. The doughnut chain worked to drive up likes on Facebook, handing out free boxes of doughnuts at malls and schools and announcing special deals on the social platform.

A recent case study from Securian Financial Group illustrates how social media can be a great tool for the financial services industry. The brand chose a relevant topic, engaged with the public, and used social media platforms – Facebook, Twitter, YouTube – to reach out to potential customers.

What were the most popular social media case studies in 2012? Based on traffic, here are the top case studies we published in the last year, from social media fails to innovative, multi-platform campaigns:

On Black Friday, Facebook and Walmart launched the social network’s largest mobile advertising campaign ever. Walmart pre-purchased the ads, “edging out” other retailers for exposure at the start of the holiday season, according to The Wall Street Journal. Was the campaign successful, and will Facebook partner with other brands in this way?

Truvia – a sugar alternative – is seeing solid results from a social media campaign asking fans to help direct the company’s expansion efforts. The campaign, entitled “Turning the Town Truvia,” asks the brand’s Facebook fans where they’d like to see Truvia – and participating fans are entered for chance to win $5,000.

Asking your customers and fans to hack your brand is about as social as a social business can get. You don’t own your brand: your customers do. And hosting your own brand hackathon is a brilliant way to find out just how far your brand can go if you let them have the controls.

“I think the reason people don’t do brand hackathons is brand managers jealously guard their tag lines, logos, and look,” says Betabrand founder Chris Lindland. If this is you, you’re not ready for a brand hackathon. Read on to find out what you’re missing.

Designer fashion label Michael Kors launched a two-week contest on Instagram back in August, asking users to share pictures of their favorite Michael Kors watch with the hashtag #MKTimeless. The contest created a huge upswing in the brand’s Instagram follower numbers, generated thousands of user photos, and led to increased engagement on Facebook.