It helps if your organization is on the radar of one of the world’s–and social media’s–most influential pop stars. But for Adam Braun, founder of education charity Pencils Of Promise, Bieber was just one building block.

While traveling on a Semester at Sea in 2005, Adam Braun met a boy in India. When he asked the boy what he wanted most in the world, the boy said: “A pencil.” Adam reached into his backpack, pulled out a pencil, and gave it to the boy. It could have sufficed as a poignant rejoinder for cocktail conversation, but the moment stirred something deeper in Adam.

Braun went on to found Pencils of Promise, which raises money to build schools that provide basic education for preschool and primary age students in remote villages. School sizes range from 20 to 200 students. In three countries the schools have served more than 4,000 students. Last month Pencils of Promise reached a milestone, marking the completion of their 50th school. And Braun and his team of 50 (10 in New York and 40 in the field) are on track to add another 50 schools by the end of 2012.

At the heart of Pencils of Promise are members of its influential social media community–namely, one Justin Bieber, who has been a spokesperson for the organization for two years. A 2011 study revealed that on a regular basis 1% to 4% of all tweets are related to Justin Bieber. Bieber himself has 20.8 million followers, and thousands of accounts proudly state their allegiance to the teen idol. Bieber is active online and off, regularly sending out information in addition to visiting projects abroad and meeting with young supporters in the U.S.

PoP’s fortune in landing one of the world’s biggest pop stars was no dumb luck. Scooter Braun, Justin Bieber’s manager, is Adam’s brother. “Having Justin as a spokesperson definitely helped accelerate our growth,” Adam Braun says. “Early on when he would talk about us, those fans just came to the website to check it out. To this day, if Justin decides to speak about Pencils of Promise we’ll see a flurry of digital activity. That’s really an opportunity to convert those people from Justin Bieber fans who know about Pencils of Promise to true fans of Pencils of Promise and create sustained engagement.”

That drive is what makes Pencils of Promise more than a passion project by a guy with influential friends and family. As invaluable as Bieber’s contribution has been, for example, it’s not the linchpin of Braun’s operation. He and his team have developed several social media initiatives designed to build an influential, active community. One, for example, called PoP Stars, is a web feature that highlights stories–usually found through Twitter or articles–from the organization’s supporters around the world. Every month, PoP community members can vote for the “PoP Star” of the month. Pencils of Promise claims to have one of the largest social media presences of any nonprofit started in the last four years.