The 53-second video showing Bryant bounding over an Aston Martin has become a hit on YouTube, garnering nearly 2.5 million views in its different versions. In just a few weeks, it's sparked lengthy-albeit fairly moronic-debates among viewers about whether it's real or not. (Not, says Nike. Like the L.A. Lakers would let Bryant run the risk of turning into the world's most expensive pancake?)

On one level, it's a marketing hit, too. "Just on the basis of word of mouth-are they building buzz and creating conversations? - it's doing quite well," says Pete Blackshaw, EVP of Nielsen Online Strategic Services and author of the upcoming Satisfied Customers Tell Three Friends, Angry Customers Tell 3,000: Running a Business in Today's Consumer-Driven World. "There are companies that brag when 2,000 people watch their viral videos."

But it's also sparked a handful of teenage copycat videos, and safety advocates are concerned. While Bryant opens and closes the video with the obligatory "Don't try this at home" legalese, "we've got a lot of kids who are looking to be famous online," says Parry Aftab, a security, privacy and cyberspace lawyer. "They are bored, and live anonymous lives, and are looking for something that would put them on top of the pack for being brave or cool or funny."

Certainly, many YouTubers (not to mention cranky parents) agree. "So when is the YouTube video [appearing] of the kids getting run [over] by Mom's Toyota trying this?" writes one. "Think no one is that stupid?"

Adds another: "You are gonna have about 5,000 kid Kobe fans who try this and all the retards who came up with this idea are gonna have blood on their hands," adds another, helpfully linking to a handful of videos, all posted pre-Kobe, of teens actually getting mowed down trying to pull off similar stunts. "THIS IS THE WORST IDEA IN THE HISTORY OF SHOE ADS!! THE WORST! LEAVE IT TO KOBE!" screams another.

While the flattening of potential shoe-shoppers is a concern, "certainly, if people get hurt as a result of this, it will turn out to be a big negative for Nike," says Ed Keller, CEO of the Keller Fay Group, a word-of-mouth research consulting company in New Brunswick, N.J. A separate question for marketers is whether this kind of buzz can drive sales. "If the online conversation is mostly about whether the ads are fake or not, and centers on how they created that effect," he asks, "does that help with overall brand momentum?"

Certainly, there's a contingent of outraged watchers: "This is as fake as Kobe," snorts one of the more polite Kobe and Nike bashers, and there's much debate about which other basketball stars might be able to pull off such a leap-for real.

But for the most part, viewers seem to be pretty fascinated with just how the spot was shot. "Most people realize that sports figures' contracts usually prevent them from even riding motorcycles, let alone leaping over moving vehicles-and this is lighthearted enough that it won't turn people off," says Blackshaw. Bryant himself has described the shot in two words that say it all: "That's Hollywood!"

Even some safety advocates agree. "Most teens are savvy enough to see through this," says Liz Perle, editor-in-chief of Common Sense Media, a San Francisco-based group that reviews media for parents. While she says the Nike video definitely "skirts the line" of what's safe, "for most kids, there's a real suspension of disbelief-they know about special effects and Photoshop." Of course, she adds, that's not to say some kid might not get hurt trying to recreate the Kobe jump. "But there will always be copy-cat behavior, and kids can find plenty of ways to hurt themselves without Kobe Bryant."

Aftab, who is also the founder of Wired Safety, a children's advocacy group, disagrees. "At some point, I think the Federal Trade Commission will step in to rule on the safety of these viral ads, just as they do for TV."

Nike, meanwhile, maintains that the video is completely safe. "One of our goals at Nike is to always consider the safety of our athletes and others, and we wouldn't want anyone to re-enact this," says KeJuan Wilkins, a Nike spokesperson. "This was done with professional editing and something people practiced and rehearsed. "

Of course, whether it sells Hyperdunks is still to be determined-the shoe isn't scheduled to hit U.S. stores until late July. "We wanted to get something out there to generate excitement and buzz as we head toward the Olympics," says Wilkins. "The beauty of a project like this is that people can watch it as much as they want and as often as they want. And many of the kids we're trying to reach live in this digital world."

Certainly, Keller says, "if you can put out a video and get a couple of million views, that will help seed a new product launch."

But it isn't without risks. "This is the double edge sword of word-of-mouth and consumer-generated media," says Blackshaw. "This is the new epicenter of consumer attention, but it doesn't always cut in the brand's best direction."

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