"There's no ethnicity flag on Twitter."

So says Isaac Mizrahi, managing director of Omnicom-owned U.S. Hispanic agency Alma. It's hard to tell whether English-language tweeters are Hispanic, or if Spanish-language tweeters are in the U.S. Hispanic market or somewhere in Latin America. So the shop developed the Social Media Lab to help marketers learn from Hispanics' online conversations. The ambitious project is already paying off in new-business pitches and positions the agency to bring in more work from existing clients.

Alma has painstakingly assembled a database of about 20,000 U.S. Hispanics active on social-media networks, and analyzes their conversations from lifestyles to brand preferences to mine actionable insights. Alma's winning pitch for University of Phoenix's Hispanic business included insights from online conversations about higher education and career advancement, providing a bigger picture. And even when Alma came in second in a different pitch, the client later approached the agency to ask about subscribing to the Social Media Lab.

This big-thinking attitude enabled Alma's revenue to jump 20% in 2013. Based on good Hispanic work for Florida Blue health insurance, Alma was invited to pitch against BBDO for the general-market account and won, as Florida Blue geared up to seek new customers under the Affordable Care Act.

"We showed them you can think multiculturally, with overarching ideas but several subtleties and cues that make the campaign work strongly in Spanish and English," said Luis Miguel Messianu, Alma's president and chief creative officer.

Steve Snell, Florida Blue's VP-enterprise marketing, said he posed two challenges in the pitch: Find a way to bring music and emotion into the campaign, and give us something that will have legs beyond a TV spot and a single year.

Alma delivered. The agency created the bilingual Florida Blue Band, singing about the health-care provider who is here for you. Brand awareness rose by 70%, and call-center volume surged 179%. Potential customers came into Florida Blue centers and used traveling karaoke booths to record their own versions of the catchy song, which were posted online.

"Our sales force went crazy over the karaoke booths," Mr. Snell said.

Alma excels at low-interest categories, making even tires and insurance -- State Farm and Florida Blue are the agency's second- and third-biggest clients -- seem fun, often with music. State Farm's Latino Facebook page has 220,000 fans, more than any other brand's Hispanic page.

To add some interest to tires after winning Goodyear's Latin America account, Alma created "Miles of stories"/"Kilometros de historia" by following Dotan, a man with a dog and a piano for impromptu street performances, on his 10,000-mile drive from Manhattan to Panama.

Alma's biggest client remains McDonald's, and part of the agency's role is to maximize the fast feeder's Latino fan base to generate influence across all segments. In one charming new bilingual spot for both Spanish and English-language TV, a Hispanic teenager works the counter as his proud parents eagerly snap pictures of their son's first job. His non-Hispanic manager tells him not to worry about it; his own parents turned up with a video camera on his first day.

Agency staff was up by 20% to 125 employees of 27 nationalities, including the notable hire of an executive creative director, Alvar Sunol, from Spain.