(FORTUNE Small Business) – Some entrepreneurs become household names; others just become household surnames, like Colonel Sanders or Mrs. Paul. Consider, for example, William Mathias Scholl, whose name probably doesn't ring a bell until truncated to its more familiar form: Dr. Scholl. Oddly enough, this doctor never had a medical practice, but he still had a huge effect on public health, forever revolutionizing foot care.

Scholl was born in 1882 in rural Indiana. His grandfather had been a shoemaker in Germany, and young Billy borrowed his tools to repair his own shoes, eventually becoming the family cobbler. At 18, he left for Chicago and began working at Ruppert's, a downtown shoe retailer, where he found that sophisticated city residents struggled with foot pain just like the farm folks he'd grown up with. Sensing he'd found his calling, he took night classes at a local medical school, focusing his studies on the foot--an appendage that by his estimation was woefully underserved by the marketplace.

As his medical acumen grew, Scholl started tinkering with foot-care devices. In 1904, at age 22, he patented a mechanical arch support called a Foot-Eazer. His customers at Ruppert's loved it, and Scholl soon left the shop to start his own business. Although he'd never worked as a doctor, he had by now received his medical degree, and the Dr. Scholl brand was born. Dressing in a stiff winged collar and a cutaway jacket in order to appear like an older, learned physician, Scholl made sales calls at Chicago shoe stores, usually employing what became his signature visual aid: a skeleton of the human foot that he produced from his pocket and used to illustrate his points.

Scholl continued to develop new products--anticorn pads, cushion insoles, exercise sandals, orthopedic shoes--and novel ways of selling them. Realizing that shoe salesmen were his foot soldiers, so to speak, he offered them podiatric correspondence courses, promising higher commissions for clerks who understood their customers' feet. After having his first $1 million year, in 1915, he sponsored a Cinderella Foot Contest in 1916 and a national walking contest two years later (contestants had to record their mileage at local shoe stores, yielding further sales opportunities). He also began cultivating foreign markets by traveling abroad, and in a famous encounter fitted a grateful Kaiser Wilhelm of Germany with arch supports.

The net result was that Scholl essentially invented the over-the-counter foot-care category. Though the medical community sometimes carped that he wasn't a "real" doctor, Scholl persevered. His business philosophy, "Early to bed, early to rise, work like hell, and advertise," was as catchy as his ad slogans ("Put one on, the pain is gone" and "When your feet hurt, you hurt all over" were among his classics). He also cut out the middleman by opening hundreds of Dr. Scholl's Foot Comfort Shops. By 1955 the Dr. Scholl Co. had 16 manufacturing plants, and "Dr. Scholl's" had become the world's third-best-known brand name.

Scholl died in 1968, having developed more than 1,000 foot-care products and a $77 million company. The firm went public in 1971, entered the Fortune 500 shortly thereafter, and was acquired in 1979 by Schering-Plough, where it's now a $290-million-a-year business. Meanwhile, Scholl's name--all of it--lives on at the Dr. William M. Scholl College of Podiatric Medicine in Chicago, home of the world's largest foot clinic--a nice validation for the doctor who never practiced medicine but viewed everyone with feet as his patient.