Since the company incorporated in May 2007, it has raised $6.5 million from a combination of investors who, Mr. Goldman said, are able to push the company on both its social mission and its profitability.

What to call these innovative businesspeople is the subject of some debate. The terms “social entrepreneur” and “social businesses” are generally used to characterize people and businesses that bring entrepreneurship to ventures that have a social mission. Yet there are those who would limit the social entrepreneur label only to those without any profit motive. A separate, but related, category are companies referred to as “socially responsible.” These are generally companies whose core business does not necessarily have a social mission, but who display socially responsible characteristics, like environmental sensitivity.

Because of the difficulty of defining these social ventures, it is hard to gauge the exact number of them, but there are indications that there is increasing interest in the idea of using business to tackle the world’s big problems. Last year, 630 people attended a new conference, Social Capital Markets, on social venture investing. According to Kevin Jones, the creator of the conference and a principal in Good Capital, an investment firm focusing on social business, two-thirds of the participants signed up after the collapse of Lehman Brothers, which he called a sign that people are flocking to what he calls a “new asset class.”

Image Ms. Bretos is formerly Floridas secretary for aging and adult services. Credit... Alex Quesada for The New York Times

Experts concede that not all social problems respond well to the for-profit model. One example could be early childhood education. “If you set it up as a business, you might be able to raise money more quickly and grow more quickly,” said David Bornstein, the author of “How to Change the World” (Oxford University Press, 2004), an often-cited book on social entrepreneurship. “But if you want to be profitable, you might find that you have to make choices that diminish the quality of your program and then children won’t learn to read as quickly. While Stanley Kaplan can make a fortune selling education to well-heeled people, providing the same services to low-income kids would probably not provide a very good income.”