Stonyfield Farm makes and sells natural and organic yogurt, and that's what it's known for in the marketplace. But the company's president and CEO, Gary Hirshberg, has always viewed Stonyfield Farm's mission as something beyond selling yogurt or some other product for profit. In fact, the company - now a thriving enterprise with $43 million in annual revenues, whose yogurt is a nationally distributed brand - was an afterthought. It was founded in 1983 to support a nonprofit farm and school dedicated to organic agriculture. Promoting that cause is still the company's guiding light. "To be a successful business leader," Hirshberg says, "one doesn't have to concede one's passions."

He might have added that running a for-profit business as a vehicle for social activism may require extraordinary work and dedication, to say nothing of financial sacrifice. Hirshberg's own experience underscores the point: Stonyfield Farm didn't earn a penny of profit in its first seven years.

Hirshberg illustrates a theme that's easily obscured by socially-responsible companies that fail: some cause-driven entrepreneurs persevere for years against long odds, and those with enough grit can sometimes make it.

Sacred to Hirshberg is buying high-quality organic milk - untainted by pesticides, hormones, or other chemicals - for his products. Enforcing the mandate requires tough standards, vigilance, and money. He purchases only from small New England dairy farmers who claim to use no recombinant Bovine Growth Hormones. His suppliers must tender an inspection certificate or present a notarized affidavit swearing that they meet his specifications. Hirshberg has had to drop suppliers who haven't satisfied the company's rigorous quality standards. For organic milk he must pay as much as 35% over the market price, according to industry sources.

Hirshberg has deputized his sister, Nancy, as the company's full-time natural-resources director, charged with keeping Stonyfield Farm's effect on the environment as harmless as possible. For every ton of carbon dioxide the company releases, it counters by planting about 40 fast-growing trees on conservation land. "Of course, we could do less damage by not existing," says Nancy wryly.