The Diet Coke and Mentos Explosion

How a lawyer and a professional juggler became a sensationand led one of the world's biggest companies to embrace viral marketing

One November afternoon in 2005, lawyer Stephen Voltz traveled to the tiny town of Buckfield, Me., to watch his friend, professional juggler Fritz Grobe, perform in a sketch comedy show. While Grobe prepared for that evening's show at the Oddfellow Theater, Voltz passed the time by dropping Mentos candy into Diet Coke bottles.

Just as another friend had predicted, the bottle exploded, releasing a fountain of soda. After doing this experiment several times, both Voltz and Grobe became so intrigued by the effect that they decided to record a video for a segment on that evening's show. "We kept thinking, are we crazy or is this cool?" says Voltz.

When the audience went wild, both Voltz, 49, and Grobe, 38, knew they had something. What they didn't know, however, was that this one day would change their lives, making them an Internet sensation and leading to a guest appearance on the David Letterman show.

At the time, the New England winter was setting in and making it impossible to work outdoors, so the pair began doing some R&D, testing various configurations of swinging, spinning, and spraying bottles to get the best visual effect. They also tried everything from Mountain Dew and Lifesavers to Moxie and M&M's.

Ultimately, they went back to Diet Coke and Mentos, drilling holes in the Mentos and stringing five or six together on a paper clip. By drilling a quarter-inch hole in the cap of a bottle of Diet Coke, the addition of the Mentos produces a geyser over 20 feet high.

When spring finally rolled around, Voltz and Grobe were ready to film. Looking like mad scientists in white lab coats and safety glasses, they set off 101 bottles of Diet Coke using over 500 Mentos.

They nailed the video on the first take, which was a relief—they had cleared out most of the Diet Coke and Mentos in nearby stores, and it took an entire day to set up and drill holes in all those Mentos. The video was set to the music of a friend at AudioBody. On June 3 the duo posted it on their Web site,, and on the video-sharing site Revver.

Sudden Fame

They told only one person, Voltz's brother, about the video. During the first part of that day, they received just 4,000 hits. But then viewers started pouring in, at a rate of 1,000 an hour.

On Monday morning the David Letterman show called and asked them to perform. Apparently the producers had heard about Fritz and Grobe from a German blog. Later that week, Mentos called to offer support. "They said, we love what you're doing, how can we help?" says Voltz. Mentos began shipping EepyBird thousands of mints for their experiments.

Unlike Mentos, however, Coke was not excited—at least not at first. On June 12 a Coca-Cola spokeswoman told The Wall Street Journal: "We would hope people want to drink [Diet Coke] more than try experiments with it." She added, "The craziness with Mentos…doesn't fit with the brand personality of Diet Coke." That summer, Voltz says, he and Grobe received two T-shirts and baseball caps from Coca-Cola (KO), along with a note wishing them well.

Voltz and Grobe went on to perform on the Letterman show at the end of June. The video the pair created, dubbed Experiment #137, would ultimately draw more than 7.5 million viewers, and thanks to Revver's model of embedding advertising at the end of videos and sharing revenue with content creators, earn Voltz and Grobe together about $35,000.

Convincing the Company

But Coke was still silent. "Initially, we didn't have anything to do with the Diet Coke/Mentos video, but the next thing you know it's on the talk shows and all over the Internet," says Tim Kopp, vice president of global interactive marketing at Coca-Cola.

It's unclear whether or not Experiment #137 inspired the company's next move. On July 9, Coke decided to revamp its corporate Web sites— and—to add The Coke Show, a series of user-generated video challenges that was created independent of Voltz and Grobe.

Finally, toward the end of summer, Coke and Google approached Voltz and Grobe about a deal. "They never told us what changed their mind, but since they've come around they've been great," says Voltz.

It seemed the world's No. 1 brand was surprised by the viral marketing phenomenon of exploding Diet Coke bottles. "It [meaning viral marketing] will happen with you or without you," says Kopp. "It was a chance for us to point a spotlight at them."

It was also a chance for Coke to reap a little publicity for itself. Experiment #214, the second video that both Mentos and Coke sponsored, has drawn over 4 million viewers. And Voltz and Grobe now appear on The Coke Show as part of one of the video challenges.

A "Huge Difference"

Voltz, ever the lawyer, isn't releasing any financial details of the deal. "I haven't felt the impact financially," he says. But, he says, he has felt a huge difference in terms of notoriety. For the future, both Voltz and Grobe are brimming with ideas, and they're eager to continue working with Coke, Mentos, and other companies to create quality online video content.

As for Coke, the company says it will continue to spend more ad dollars online. "We really do take it in a serious way and we are absolutely committed to reinventing marketing," says Kopp. "Our percent of ad spending is following consumers online."

Voltz says he's amazed at the potential that viral online videos have created, not only for himself but for his many friends who do sketch comedy. "You don't have to wait for a Hollywood studio," he says. "Now, if you have work that resonates with others, it's a lot easier to get to your audience."

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