Before 20th Century Fox released the film Devil's Due in January, New York City-based Thinkmodo built a robotic, but realistic, devil baby and left its stroller unattended on the streets of Manhattan. The prank was filmed, along with the reactions of terrified New Yorkers. The results? On YouTube, the video has been seen more than 43 million times--and the critically panned Devil's Due pulled in more than $8 million in its opening weekend. Welcome to marketing by freak-out.

James Percelay, 53, and Michael Krivicka, 37, founded Thinkmodo in 2011. (Percelay is a former Saturday Night Live producer; Krivicka, a filmmaker.) The original idea? To create crazy but realistic viral productions.  

And they've done just that over and over. There was the automatic, head-shaving helmet video. And the computer nerd who seemingly hacked into the giant screens in Times Square. (That last one was a promo for the film Limitless, a thriller starring Bradly Cooper and Robert De Niro.)

Of course, there's no equation for creating a successful viral video campaign. They're as risky as they are difficult to pull off: When an attempt at trickery goes wrong, it can leave a lasting bruise on a brand's image. Yet Thinkmodo's daring projects have not only always avoided crisis, they've gotten better over time. Since its launch, the company has produced campaigns for 14 clients, including an underwater nightclub video for luxury watchmaker Technomarine.

"There are many companies out there with a value proposition that is implicit or explicit: We will make a viral video for you product or service or company. And that is an almost impossible promise to make," Altimeter Group Analyst Rebecca Lieb says. That's why she is so impressed with Thinkmodo's repeated success. "It's unusual. It's laudable. And it's a very, very strong testament to their creative abilities," she says. 

With each production, the team temporarily grows. "We expand up to 50 people based upon the project, and then we contract to our lean mean size. Everything we do requires a whole different army," Percelay said. 

So are Percelay and Krivicka sweating about whether or not they can keep it up? Maybe. But lucky for them they work well under pressure. "We know what we can do," Percelay said. Thinkmodo will probably pull in somewhere between $4 million to $5 million in revenue this year. "The results," says Percelay, are "our selling card."