There aren't too many doctors in the village of Hari Ke Kalan, in the Punjab region of northern India. But for $1, residents who bicycle to a new health clinic can get an appointment with a physician appearing on a large-screen television and beamed in over broadband Internet.

The clinic, built by a startup called Healthpoint Services, is one of a network of eight "e-health points" that the for-profit company has built in India as part of a growing effort by entrepreneurs to capitalize on the rapid expansion of cellular and broadband access in the poorest parts of the world. With successes such as text-message-based mobile payments taking off in some countries, many experts see medicine as the next major application of technology in poor nations.

In India, the rural population often has little access to medical services. When villagers get sick, they must either make a costly trip to visit clinics in big cities, take their chances with poorly trained local practitioners, or go to free government clinics that are staffed by physicians only a few hours a week.

Healthpoint's clinic in Hari Ke Kalan is a money-making enterprise, says  Al Hammond, Healthpoint's cofounder. It charges about 80 cents for a consultation with a doctor and about a dollar for diagnostic tests, such as blood tests to measure blood sugar or check for infections. "For a family with an income of $3 to $4 per day, that's affordable, and we can cover our costs with those prices," he says.

Hammond, who calls himself a "serial social entrepreneur," says he decided after studying low-income consumers that a for-profit company had a better chance than a nonprofit of delivering medical care to millions who need it. "It only makes sense to do this if we can scale enough to change the health-care system," he says. "I wouldn't, as a startup, try to change the U.S. health-care system. But in rural India, there is no health-care system, so it's much easier to innovate there."

The company was initially funded by U.S. angel investors who were attracted to the social impact of the venture, including the cofounders of Athenahealth, a producer of electronic medical records technology based in Watertown, Massachusetts. Hammond says Healthpoint has quickly become self-supporting and that the clinics are "cash-flow positive."

Each Healthpoint clinic typically starts as a water service, where local families can fill jugs with clean water for a monthly subscription fee of $1.50. Hammond calls the service a form of preventive medicine, and not only because many infectious diseases are spread through tainted water. Villagers who come for water often end up getting seen by a doctor. In addition to eight clinics, the company has 16 water points in India, with plans to expand to South America and Africa.