The social media sphere is an increasingly noisy place, especially for brands. But hiding somewhere in the static are strong signals from companies reaching their customers in innovative ways. The Social Business Index from Dachis Group provides a (free) real-time ranking of more than 30,000 global brands based on their social performance. Every week we're taking a tally of who's getting heard, what they're saying, and why it matters.

Zynga is the star of the Social Business Index this week, zooming another 25 ranks up to number 11. (We featured Zynga's skyrocketing success since being added to the Index last week.) Otherwise, the top ten are gridlocked and the big food companies like Mars, Starbucks and Kraft are losing footing. We're starting to see the springtime creativity come out of brands further down the ranks, however. American Express is learning more about how to use Twitter and Foursquare's API to win fans organically. Verizon is figuring out Facebook contests with great success. And DreamWorks. Well, DreamWorks needs some work.

American Express flipped the switch on a couple of innovative social strategies this week, bumping their rank on the index ten spots to No. 64 this week with initiatives revolving around offers. It's a pretty smart move for a credit card company, especially the bit about unveiling the campaign at SXSW. Earlier this month, AMEX introduced a feature that allowed you to sync your card with your Twitter account and thus receive custom offers based on how you tweet. Mediabistro's Lauren Dugan explains the program in a blog post: "You could save $5 the next time you’re at McDonald’s, or $20 off your next Whole Foods bill. And all this just by tweeting a few AMEX-inspired hashtags." Sort of hard to say no to 20 free dollars just for one little tweet, no? About 100,000 people felt this way and followed AMEX on Twitter over the past few weeks. On Foursquare, the strategy is very similar except it involves check-ins. We apologize in advance for the cliché: You've gotta spend money (and tweet about it) to make money.

Verizon is taking advantage of all the excitement around the new iPad by boasting about its 4G LTE offerings. The telecom company moved up 9 spots on the ranks this week, thanks in part to its "30 tablets in 30 days" Facebook promotion. This contest works just like all of those spammy "Win a free iPad!" emails and banner ads you see on the Internet, except that Verizon is actually giving away a tablet a day for the next 30 days. To make the whole campaign really interesting, Verizon is requiring its Facebook fans to submit a photo of a land- or cityscape on the brand's page. You have to 'like' Verizon in order to even read the rules of the contest (PDF), and then the company is coy about how the winners will be selected. (It's decided by a vaguely scientific formula and a panel of judges.) Of the approach, Dachis Group analyst Shadi Afshar says, "It’s a really great opportunity for aspiring photographers and mobile enthusiasts -- selected photos will be seen by more than two million people -- and it also works in product mentions into the photo through the image credits." The real funny catch: They're not giving away iPads. The winners get a Droid Xyboard by Motorola.

This week is one of those rare weeks when we feature a failed campaign. DreamWorks did such a good job building a following around their Shrek brand, but totally dropped the ball causing them to fall a whopping 35 ranks in the Social Business Index. The Dachis Group attributes the tumble to a simple lack of attention paid to the 23 million fans on the Shrek Facebook page. "Specifically, from March 6th-12th, the brand didn’t post any updates or content on its page," Afshar told The Atlantic Wire. "This lack of activity may seem minimal for most brands, but when a brand is speaking to 23M passionate and eager fans, it needs to maintain consistent participation and communication to remain relevant." Simple takeaway: It's hard to win fans, but it's easy to keep them. Pay attention. Talk back. And don't disappear for a week. This whole social media engagement thing is kind of like dating, except without the trick where you don't call the other person for seven days. That's just negligent.

Methodology: A project of the Dachis Group, a social business professional services group, the Social Business Index analyzes the conversations on social platforms such as Twitter, Facebook, YouTube, and others. The index, which currently covers approximately 25,0000 companies and 27,000 brands, detects behaviors and activities exhibited by these companies and analyzes their execution and effectiveness at driving outcomes such as brand awareness, brand love, mind share, and advocacy. The Atlantic Wire takes a snapshot of the rankings at the end of the day on Sundays.