"This might sound crazy, but I didn't understand why people didn't think it was going to work," says Shannon May, co-founder of Bridge International Academies. In 2008, she and her husband, Jay Kimmelman, set out to raise money for a chain of thousands of schools they hoped would serve 10 million students across the developing world. "Everybody wanted us to have built one school first," says May. "I was like, anyone can build a school."

When your goal is to eradicate world poverty through education, scaling slowly isn't an option. Bridge International Academies is only seven years old, but the for-profit company has already built 300 primary schools serving 100,000 students in Kenyan slums and villages. Having won over high-profile investors--including Bill Gates, Omidyar Network, and Khosla Ventures--Bridge is opening a new school every 2.5 days. Bridge refers to its scaling model with the deceptively simple moniker Academy in a Box. In fact, it's an elaborate system combining standardization, technology, best practices, and data. The founders' experiences add up to a master class for entrepreneurs working in the developing world. "Bridge is pioneering not only a business but an entire approach," says Matt Bannick, managing partner at Omidyar Network. "I think they'll have a profound impact that ultimately will enable us to provide much better education to so many people."

Bridge's roots lie in rural China. In 2005, May, then a doctoral candidate at UC Berkeley, was conducting fieldwork on a project to create an experimental eco-city. (Kimmelman, who had recently sold his successful startup, Edusoft, kept her company.) While teaching English in a primary school, May was shocked by the conditions and indifferent staff. "No one cared about these kids," she says.

May and Kimmelman decided to, first, get married and, second, do their bit to change the world. "If you can raise the floor of what a generation of children know," says May, "then you've raised the floor of what that country can do as those children become adults."

Wary of China's strict regulatory climate, the couple focused on sub-Saharan Africa. They visited schools and interviewed teachers and parents. "There were abysmal learning rates," says May. Like many African nations, Kenya was awash in schools, both public and private. Private schools can be expensive--as much as $20,000 a year--and vary drastically in quality. Public schools are plagued with problems, including no-show teachers who score lower on tests than their students. Many students leave the eighth grade unable to read or count.

Even when they had just two schools, the founders did everything with an eye toward how they would function with thousands.

The first Bridge Academy opened in the Mukuru slum in Nairobi in January 2009. The second launched a few months later. Bridge, which costs less than 70 percent of what the local private schools charge, reports higher scores in reading and math than public-school students taking the same tests.

In the early days, the founders repeatedly bumped up against challenges peculiar to the region, including fending off whisper campaigns that Bridge was a devil-worshiping black-magic society. "You have to bring in pastors who pray and say, 'This school is not cursed,'" says May. Such accusations still bubble up, but "now parents rise up to defend the school. That's a sign of how far we've come."

Bridge doesn't release revenue figures, but it serves 100,000 students paying an average of $6.50 a month, 11 months a year. Bridge projects it will reach half a million students by 2016, when it expects to become profitable.

The founders decided to go the for-profit route because they thought it was the best way to fine-tune the schools and scale quickly, says Kimmelman, speaking by phone from Kenya. "When parents think our schools are doing well, they pay fees, tell others to come, and our schools are sustainable," he says, after apologizing for a dropped call caused by a passing herd of zebras. "If a school wasn't performing, they would pull their children away, we'd lose revenue, and have to close the school."

And, of course, Bridge only succeeds at scale by amortizing costs across many students. Bannick cites a study showing that over 30 years, 201 nonprofits scaled from 0 to $50 million. In that same period, tens of thousands of businesses had done so. "For-profit entities generate the capital to help scale," he says.

Even when they had just two schools, the founders did everything with an eye toward how they would function with thousands. Bannick says it was Bridge's ability to "innovate, replicate, scale" that persuaded Omidyar Network to become its first major investor, in 2009. Says Bannick, "Every step of the way they have been very thoughtful about, Do we have the systems to make it work with a dozen schools? With a hundred?"

Scaling fast while hitting the necessary quality and price points in a place with little infrastructure required Bridge to control every aspect of building the schools. "It only works if you have a construction company, a curriculum company, and everything else under one roof," says Kimmelman.

Launching a school begins with site selection: a combination of demographic research and surveys. Having established demand, Bridge builds the schools: simple structures of sheet metal and wood that are customized for climate. A more formidable challenge is hiring. Every four months, Bridge interviews roughly 10,000 people in order to fill 1,400 slots in new schools. All candidates are tested on a variety of subjects, and the most promising undergo five weeks of intensive training.

Systems follow teachers into the classrooms. To ensure teachers are present, Bridge created software that runs on refurbished tablets. When teachers arrive at school, they use the tablets to check in via Wi-Fi. If they're late or don't show up, Bridge headquarters is automatically notified. The system also automatically contacts substitutes.

To create the curriculum, Bridge employs teams of education experts in Kenya, India, and Cambridge, Massachusetts. They write scripts for each lesson, making sure the material meets national requirements and is culturally appropriate. Following the scripts, teachers across the schools theoretically speak the exact same words at the exact same time, a model that has its share of critics. May argues that though the scripts limit the creativity of the teacher, "that does not mean it takes away from creativity for the child."

The founders hope that as teachers master material from their scripts and undergo training, a larger corps of proficient educators will emerge to serve all Kenya's schools. The needs are similar throughout sub-Saharan Africa. By early 2015, Bridge will have academies in Nigeria and Uganda, with India soon following. The company recently rolled out a lunch program, and Bridge-fabricated school uniforms launch at the end of 2014. "No one else is providing our customers with these services," says May. "When you treat them as a market, you can use volume to drive down the costs. So we can make much higher-quality products--education, food, uniforms--available than they ever had before."

On quality, Esther Wambui agrees. Her three children used to attend another private school. Now they're enrolled at a Bridge school, which Wambui says is far superior. "Now my children can speak English," she says, high-pitched squeals and giggles audible in the background. "They love their teachers. They get homework.

"They are doing much, much better," says Wambui. "We are very happy."