Take a good hard look at your toenails. are any of them flaky, yellow, and cracked? Then you, too, might be suffering from the heartbreak of onychomycosis.

No smirking please. Onychomycosis is an ugly fungal infection afflicting the toes of more than 35 million Americans. On occasion, it can be excruciatingly painful. More commonly, however, the disease turns toenails into unappetizing strips of calcified decay. Yech.

But what makes onychomycosis so infectiously intriguing is not its tendency to attack toenails while leaving fingernails untouched, nor its stubbornness in taking root in nail beds. No, what truly makes this parasite provocative is its profitability. In barely seven years, treating onychomycosis has grown into a business worth hundreds of millions of dollars annually for Novartis, one of the world’s largest pharma firms. Millions of people have paid roughly $1,000 – more than $100 per infected toe – for pills made by Novartis that rid them of the evil fungus causing this unappealing condition. That’s real money.

Remember, we’re not talking baldness, depression, or erectile dysfunction here; we’re talking toenails. “Toenail tech” is so utterly devoid of any charm or sex appeal that the ability to turn a toenail treatment into a fast-growth, high-margin business says something important about the nature of innovation.

Novartis’s toenail triumph is particularly illuminating because its original innovation salvo seriously misfired. When the firm launched its first marketing campaign for its new drug Lamisil in 1997, it made a crucial analytical error that nearly condemned the medication to marginality. In the end, Lamisil’s rebound and ultimate success required Novartis to ignore its most obvious selling point.

Novartis launched Lamisil with the advertising slogan “Let your feet get naked.” As Lamisil brand director Christine Sakdalan puts it, “The most intuitive insight was this was a very ugly disease – it looks ugly and feels ugly. That was what the research way back when emphasized, and we went with it. That was the low-hanging marketing fruit for us.”

The campaign succeeded in raising both consumer awareness and response. Unfortunately for Novartis, all this publicity failed dramatically to translate into the desired revenues. Why? Because the overwhelming majority of doctors didn’t see beautiful “naked feet” as a medical goal worthy of their prescriptions.

“[After-launch] research revealed a fundamental disconnect between patients and physicians that needed to be closed,” Novartis chief marketing officer Kurt Graves observed in a trade magazine article. “Patients didn’t realize the cause of the condition or the potential seriousness. Physicians, who had never heard from patients about their nail condition, didn’t believe it was a problem and saw it more as a cosmetic issue that could be self-managed or treated with over-the-counter medications.” In other words, Lamisil’s future commercial success depended less on the patient’s aesthetic desires than on the physician’s perception of medical need.

Consequently, Novartis completely repacked, repositioned, and remarketed Lamisil. Beauty became the happy by-product of Lamisil’s new promise: killing a stubborn and potentially painful fungal infection. Doctors were asked to be doctors treating an infectious threat rather than beauticians preparing people for summer’s barefoot strolls. Not incidentally, stressing the medical over the cosmetic elements helped many possible Lamisil users feel less self-conscious about complaining to their physicians about tender toenails.

The clearest indication that the repositioning was succeeding came when the female-to-male ratio among Lamisil users quickly shifted from 70:30 to 50:50. Men typically care far less about how their toenails look than women do. Decosmeticizing Lamisil made it a more “serious” medication for doctors to prescribe.

The cynical interpretation of Lamisil’s success is that creative advertising and promotion can turn even a toenail therapy into a bestseller. There’s almost a billion dollars’ worth of truth in that. But as with Lamisil’s initial marketing campaign, the obvious conclusion is misleading.

The better story here is that Novartis corrected a huge marketing innovation error by learning – and relearning – that it needed to appeal to the medical community’s sense of professional self, not just the Lamisil user’s sense of vanity. In truth, the most important learning about innovation adoption almost always takes place after a product has been launched – not before. More often than not, innovators discover the real obstacles to their success – and the opportunities for growth – months or even years after introducing a new technology.

Does Lamisil represent a medical breakthrough for innovators to emulate? Absolutely not. But the ability to innovatively rebrand, reposition, and profitably rechannel a $1,000 medication for toenails most assuredly does.