The Fortune 500 social media stars

General Motors - #7

GM has been through a reformation in the last few years—bankruptcy followed by an IPO for starters—facing changes that can drastically alter a company's relationship with its customers. That's why GM's social media campaigns are particularly important, says Mary Henige, director of social media and digital communications at GM. "They humanize the company," she adds. The automaker's "Faces of GM" video blog, one of three corporate blogs available to the public, literally puts company employees in front of camera to share insights and perspectives. (The company's "FastLane" blog, an old-timer in the blogosphere, debuted back in 1994.) While the company has large followings on both Facebook and Twitter, it actually pegs Google+ as its largest channel, offering photos, news and hangouts to over 1.3 million followers. Every Friday—known as "Fan Friday" to GM's social teams—the company changes its Facebook cover photo to one submitted by a customer. A 20-member customer assistance team monitors all of GM's social media accounts sevens days a week to answer questions or deal with complaints.

Aflac - #118

The Aflac Duck isn't just a television personality anymore; it is also a social media superstar. The Aflac company mascot has a verified Twitter account (nearly 20,000 followers) and more than 350,000 Facebook fans, an impressive number considering the how difficult it is to type without fingers. Aflac has established a strong presence on social media despite a product that offers up significant social media challenges. "Health insurance isn't something people want to think about at all," says Michael Zuna, chief marketing officer for Aflac. "The Duck allows us to give Aflac a voice. He's very relevant and timely and engaged in America." Rarely will you find the Aflac Duck posting about corporate news, but philanthropic endeavors are another story. In collaboration with social platform GetGlue, Aflac had more than 540,000 people check-in during the Duck's appearance at the Thanksgiving Day Parade, a feat that raised over half a million dollars in matching donations from the company. (Aflac pledged $1 per check-in.) Thanks to regular philanthropic posts on the Duck's Facebook and Twitter pages, Aflac raised over $2 million for childhood cancer projects in 2012.

Visa - #260

Visa's new social media journey started with last summer's Olympic Games, of which the company was a major sponsor. Visa went younger on its marketing team, hiring "digital natives" to make all of its social media content "irresistibly shareable," says Antonio Lucio, Visa's chief brand officer. "[We] turned everything on its head." The result was the company's most successful social media campaign to date, with over 60 million total engagements and 48 million unique YouTube views during the three-week-long games. Visa also hired an outside marketing firm, MRY, to handle increased day-to-day engagements across all of its platforms. The next major stop on Visa's social media journey: the 2014 World Cup in Brazil, where the company will once again be a major sponsor. "Our objective," says Lucio, "will be to beat the Olympics."

Facebook - #482

After all of the discussion in recent years about Facebook's value as a company, it may seem hard to believe that 2013 is Facebook's first year on the Fortune 500 list. And as much as people like to criticize the company's ad strategy or privacy issues, there is no doubt that Facebook is the crown jewel of social media. The site announced in October that it had reached 1 billion active monthly users, and recent product announcements have spruced up the site's timeline and committed Facebook to a (much) stronger mobile presence with the unveiling of Facebook Home. The company makes this list not only because it provides the platform all others in this category are utilizing, but because Facebook also uses social media effectively to engage consumers. Of course, Facebook does have a Facebook page (with more than 90 million 'likes'). The corporate blog is easy to find—simply log into Facebook—and the company hasn't ignored other social media channels as a way to connect with potential users: Facebook has over 7 million followers on Twitter.

AT&T - #11

AT&T hit a homerun with its most recent string of "It's not complicated" television commercials. The ads, featuring children explaining why AT&T's attributes are important to customers, have formed a strong part of AT&T's recent social media campaigns, too. Log on to the company's Facebook page and you'll see a number of posts under the hashtag #itsnotcomplicated, including bonus videos and behind the scenes clips from the commercials. The clever spots have also sent viewers to the corporate YouTube channel—the "It's not complicated - Grandma" video has over 750,000 views—and the company uses the same hashtag on Twitter to alert followers of news or features related to the ad campaign. As the lines between social media campaigns and traditional marketing (i.e. print or television ads) continue to blur, AT&T has kept pace. The company uses its social media presence to do more than simply make users laugh, though. During last month's bombings at the Boston Marathon, AT&T tweeted out important information about network and Wi-Fi availability, plus the locations of phone charging stations to more than 210,000 followers.

Caterpillar - #42

For a business-to-business company, connecting with consumers on social media is no simple task, although you wouldn't be able to tell by looking at Caterpillar. While the company may turn some heads with its product photos on Facebook and Twitter (the Cat D11 tractor weighs nearly 230,000 pounds!), it's Caterpillar's videos on YouTube that truly show off the company's powerful machinery. The corporate YouTube channel has well over 11 million views, and Caterpillar offers videos in a number of different languages, including German and Spanish. The videos are more than simple tractor images, however, and the company successfully strikes a balance between fun product content and high-level industry conversations, a nod toward Caterpillar's dedication to educating its fans.

Oracle - #80

When it comes to social media, Oracle has taken the shotgun approach, creating dozens of accounts on every platform in hopes that a few will stick. The company has close to 70 different Twitter accounts listed on its corporate webpage, highlighting what we can only assume is every department or product the company has to offer. (Billionaire-CEO Larry Ellison has more than 36,000 followers despite posting only a single tweet last June where he took at a stab at rival SAP.) Oracle hasn't limited this approach to Twitter. It has close to 50 affiliated Facebook pages and even more LinkedIn groups. The company's social reach extends beyond those simply interested in enterprise software, however. The Oracle Team USA sailing team—preparing for the America's Cup which will take place this September in San Francisco—brings plenty of extra recognition by posting pictures on social sites like Pinterest, Instagram and Tumblr. For a company that may otherwise lack a visual connection with users, Oracle is now offering up some of the most impressive photos in sports.

Safeway - #62

Warning: don't visit Safeway's Facebook page on an empty stomach. Food bring people together, and pictures of delicious meals make users want to run out to the grocery store. At least that seems to be the approach taken by Safeway for its social media campaigns. The grocery giant has made grocery shopping more exciting by offering up recipes, coupons and photos of elaborate meals on all of its social channels. Safeway has nearly 1 million Facebook likes and users can click on appetizing photos from the site to get necessary shopping lists and recipes. A customer support team responds to users complaints or questions on a daily basis for all of Safeway's social accounts. Plus, the company's convenient phone app allows users to bring electronic coupons with them anytime they head to the store, minimizing the need for coupon clipping.

Coca-Cola - #57

If anyone was doubting Coke's dedication to social media, think again. The company took some flack in March after an in-house study found that social media didn't impact short-term sales, but if anyone knows the power of long-term branding, it's Coca-Cola. Social media is most powerful when incorporated with other mediums, said Wendy Clark, senior vp of integrated marketing communications and capabilities, in a post on the company's blog. Coke routinely integrates its social and television efforts and has over 63 million Facebook likes and another 709,000 followers on Twitter. The company uses both platforms to promote Coke-sponsored events like American Idol or last summer's Olympics. Whether or not social media efforts increase short-term sales, Coca-Cola is going after lifelong customers -- and they appear to be doing just fine.