????An oilman with a love of zebra, cheetahs and ostrich breaks into the footwear field.

????By Megan Erickson

????(Fortune Small Business) -- Before launching Zelli Shoes in 1996, Tom Mantzel was a Fort Worth oilman with a colorful side business: breeding exotic and endangered animals.

????His Fossil Rim Wildlife Ranch imported dozens of species, including zebras, cheetahs, antelopes and rhinoceroses. When Mantzel sold the center in 1987, he walked away with the unique ability to cut international deals on rare animals. A decade later he leveraged that experience to gain a toehold in the $25 billion footwear industry, crafting upscale men's shoes out of (non-endangered) ostrich, crocodile and javelina leathers. The shoes sell for $200 to $1,000 a pair at Nordstrom (JWN, Fortune 500) and specialty retailers. Mantzel says that Zelli, which he launched with $200,000 in startup capital, now posts seven-figure annual revenues.

????He chalks up Zelli's success to his unconventional skill-set.

????"You can't just pick up the phone and call Africa for a couple of cheetahs," he says. "If your paperwork is not precise, the cheetahs go back. You could move crack cocaine easier than exotic animal products."

????But there's also a simpler skill at work: good old-fashioned customer service. Mantzel sends a handwritten thank-you note to each customer who buys a pair of Zelli shoes online.

????Sometimes they take the time to thank him too. Robert A. Pelham, a client from Chicago, wrote, "I just received my shoes today. The style and craftsmanship are impeccable. In today's world, where everything is made by a machine, it's nice to come across work someone has put some pride into."