Few products have made as much of a splash recently as the Shake Weight, a dumbbell-like product that debuted a year ago. Versions of the Shake Weight's direct-response TV ad have racked up more than 3.6 million views on YouTube. The informercial has also inspired a parody on Saturday Night Live and logged dozens of appearances on TV talk shows including Ellen. ("This is real," the host told her audience. "Do not blame me.") All of the unexpected attention has helped propel FitnessIQ, the company behind the $19.95 product, to more than two million in unit sales. With a Shake Weight for Men product line recently launched, Inc. caught up with FitnessIQ's CEO and the Shake Weight's inventor, Johann Verheem, about his inspiration for creating the product and its smirk-worthy ads.

So how did you come up with the Shake Weight?

The basic principle of using this kind of inertia in exercise was something first done in the '90s, to create weighted resistance, and I thought there was more potential there. There was a product that was sort of a bow that you shook, but the exercise was really unfamiliar to people, so it didn't do well. For people to understand it, I figured you'd have to integrate this idea of dynamic inertia into a dumbbell. So, I developed the Shake Weight with our design group in Taiwan, and had it patented and prototyped, and then it sat around for a year. Ironically, we were just not sure you could sell a dumbbell on TV. Then, I read an article about Michelle Obama's arms, and how more women wanted the right to bare arms, to show off their arms. And I thought that suddenly it was the perfect time to come out with the Shake Weight.

Why do you think this particular product took off?

You know, there are a number of good business reasons the Shake Weight took off. It's a good product that fills a real need, and there's science behind it. There's not another great product out there already that specifically works women's biceps. Women don't like heavy gym equipment that's designed for men to bulk up – most of the weight products on the market are designed for weightlifting. I mean, when you look at it, we're still using the same dumbbell as in the Roman era.

Because of the unique way the Shake Weight works, you can leave it on your coffee table, just do a couple minutes here and there, and see results.

Of course, the reaction to the Shake Weight wasn't strictly about what a good upper-arm workout it might be. How did the product's viral popularity come about?

We were doing a very quiet test one weekend, spending $10,000 to $20,000 on ads and treating it as a focus group. We did this with Shake Weight, and it did fine on its test weekend. On Monday, we came in and said, "It did okay, but nothing special."

By midday Monday, our web hosting was calling saying servers were crashing due to immense traffic. We were shocked – it was going viral.  By Tuesday, it was on Jimmy Kimmell, and then The View. By Friday, we had millions of hits on the video, and people were making fun of it. Then Ellen picked it up, and featured it on several different programs. I mean, that was amazing, because even though it comes with a laugh, the product placement for those three minutes of air-time would have cost us millions to buy.

You can't design these outcomes. They take you by surprise.

How much do you believe the viral appeal contributed to sales? I mean, are people buying a Shake Weight because they want toned arms or because it's funny?

This product definitely has a split personality. Scientifically, it is a sound product that creates results. We had two different studies done at San Diego State and by a private company that does work for NASA. The research shows that when you use the 2.5-pound Shake Weight, it burns as much energy as using a 12-pound dumbbell.

So we had incredible evidence on a product that worked, but it also looked provocative. It's not just that sex sells, but one of the other things very important in direct selling, in infomercials, is that a product looks different enough for someone to stop and watch it. And that movement you make with a Shake Weight, well, it looks different.

That's one way to put it. Sure, infomercials can be a bit steamy – think back to the Power Rider, and Suzanne Somers and the Thigh Master – but isn't this different?

I think there are sexy bodies selling lots of things—clothes, magazines, fitness equipment—all the time. There are a lot of 30-minute infomercials that use sex and good-looking bodies to get people's attention. We probably got more attention than most because our product was funny. And back when we were making the show, there were a couple of jokes going around the set about what it looks like if you do it a certain way. But that wasn't our master plan and we've had to spend a lot of money on PR so people knew it actually worked.

What about the Shake Weight for Men – was that a trickier video to make ready for marketing? 

Well, in the men's there's no room for sexual innuendo there, because it's such an intense workout. We did it with Navy Seals and Army Rangers, and saw if they could do it for three minutes. They couldn't.

But in the women's infomerical, there is room for innuendo?

The lighter device for women is for toning, when the one for men is a really tough workout. We never intended for the women's device ad to have innuendo. We had a bunch of people here from the industry, and a lot of women on the set, and they didn't make many comments. But it depends how you shake it as well. If you do it based on the three exercises that we have laid out, it's not that suggestive. Some of the women would say, though, oh if you shake it this way it looks like…well.

Beyond the infomercial, how else are you selling the Shake Weight?

Our sales come primarily from the infomercial, or from consumers going directly to the website. But also the Shake Weight is the No. 1 fitness product in WalMart, Walgreens, and Bed Bath and Beyond. We've gone international as well. The Shake Weight launched in the U.K. only a month after it launched in the U.S. Being viral online really helped us build a global awareness of the product. We could track traffic on the Web from the start, and it was being followed on the Web basically everywhere in the world, so we immediately filed for the international trademarks and for the URLs in foreign countries, so we could expand. And this born-in-the-U.S. way of selling is still part of the American dream that Europeans love.

You say you enjoyed the Ellen product appearances, but what about when Saturday Night Live did an infomercial spoof of your Shake Weight ad's potential to be sold as a product in and of itself?

I think it was hilarious. I think it was well done, and I'd love to be selling the commercial myself for $19.95. I don't think it hurt us one bit.

What's next? Is there a way to duplicate this success?

What's interesting about our industry, infomericals, is when something takes off, it just really becomes the dominant brand in the industry. Think about the George Foreman Grill. Or Proactiv, which is definitely the dominant acne solution in the whole market.

What works in the direct response business is the storyline – we need to know what the story is with the product before we finish the product. It needs to be different enough for people to stop and watch. We can't just say, here's another DVD player. We ask: what will motivate people to take action. You also need a critical mass of people to see this as very innovative. In fitness, what sells is at-home exercise, and they look at the thing and wonder, will I actually do that? Part of our job is to get them motivated to exercise.

The PR has been good. I'd love to do it again. But while part of it is planned, there is something you just can't duplicate. You can create something that's very suggestive, but that doesn't work as a product. And if you can't make something that's actually useful, it won't sell on suggestiveness alone, or be a good product.

Editor's note: This isn't Verheem's first company. His last business, Application Technologies, was profiled in Inc. in The Start-Up Diaries, a series that tracked a handful of entrepreneurs through the start-up process. Verheem sold the technology-licensing firm for approximately $4 million after 18 months.