Jay-Z performs onstage at the 2014 Global Citizen Festival to end extreme poverty by 2030 at Central Park on September 27, 2014 in New York City.

On Saturday, 60,000 fans will swarm Central Park's Great Lawn in New York City to see Cardi B, The Weeknd, John Legend and other pop stars perform at the annual Global Citizen Festival. The cost to attend this event? Free — as long as you're willing to call your congressperson, sign petitions or tweet in support of certain causes. It's all part of advocacy non-profit Global Citizen's strategy to end poverty by 2030 with help from tech-savvy millennials. To do that, Global Citizen has gamified giving back.

Getting in the game

Gamifying something means applying typical game rules — like a points system and rewards — to a task in a nontraditional genre such as social activism. In the case of Global Citizen (other than a few VIP tickets that can be purchased), the only way to attend one of organization's official, star-studded concerts (held in locations from New York in the U.S. to India and Germany) is via its app. Through the app, participants can earn points by performing acts for social good. Signing a petition to reduce plastic waste gets you one point, for example, while sending an email to help end child marriage is worth three points. After collecting enough points, users enter a drawing to win festival tickets. It's an approach that aligns with the way young people do activism, and given that millennials now outnumber baby boomers, its a generation organizations need to survive and thrive. "There were a lot of young people scratching their head saying, 'I don't have much disposable income. How can I make a difference?'" Mick Sheldrick, Global Citizen's vice president of global policy and government affairs tells CNBC Make It. Indeed, millennials give less money to charity than older generations but spend more time volunteering, according to research from the Case Foundation's 2015 Millennial Impact Report. Millennials donated an average $580 over the previous year, according to a 2017 report by nonprofit consultancy Dunham + Company. (Gen-Xers and baby boomers gave an average of $799 and $1,365, respectively.) Global Citizen offers a way to do something rather than donate, plus participants have the incentive of a pretty good prize. Tickets to a concert that brings together Cardi B, The Weeknd and John Legend alone would be worth about $500 a piece based on previous demand, according to ticket resale site TicketCity. "We don't live in a vacuum," Mick Sheldrick, the organization's vice president of global policy and government affairs says. In other words, you can care about ending malnutrition in Mozambique and Cardi B's newest album. "And that's where the concept of gamification came in."

Eddie Vedder and Beyonce perform onstage during 2015 Global Citizen Festival to end extreme poverty by 2030 in Central Park on September 26, 2015 in New York City. Kevin Mazur | Getty Images Entertainment | Getty Images

How it translates to change

"Your voice can be far more powerful than a donation," Sheldrick tells CNBC Make It. "We've always operated on the premise that we're not after your money, we're after your voice." Global Citizen isn't the first to gamify activism in lieu of donation. Free Rice, for example, has users answer multiple choice vocabulary questions and for every correct answer 10 grains of rice are donated to the World Food Programme to help end hunger. And U.K.-based charity Depaul UK created an app where the user has to care for a homeless person to teach social responsibility. But Global citizen does it on a large scale. "We are interested in the big public policy solutions that can really drive change at a huge systemic, structural level," says Sheldrick. Since Global Citizen doesn't collect money from app users, to measure impact it counts the number of activist actions carried out. To date, participants around the world have completed 19 million actions, according to Sheldrick. That influence, he says, has led to $37 billion in commitments to fight poverty from world leaders. Of that, Sheldrick says $10 billion has already been paid. Of course, Global Citizen also relies on influencers, both to play the festival (where where musicians share the stage with business and world leaders) and to speak out.

Rihanna performs onstage at the 2016 Global Citizen Festival In Central Park To End Extreme Poverty By 2030 at Central Park on September 24, 2016 in New York City. Kevin Mazur | Getty Images Entertainment | Getty Images

When asked for an example of a successful campaign, Sheldrick cites a partnership with Rihanna. Last year, the singer used Twitter to ask world leaders for global education funding through the Global Partnership for Education, for which she is the global ambassador. "Step up w/ me and be a @GlblCtzn !" she tweeted. Rihanna went on to tweet world leaders individually, including French President Emmanuel Macron. The result was a Global Partnership for Education conference held jointly by the French president and Macky Sall, the president of Senegal, with Rihanna in attendance, with $2.3 billion pledged for education, according to Global Citizen. Rihanna tweet Everyday Global Citizen participants also contributed over 260,000 activist actions to the campaign for education funding. More recently, Global Citizen participated in a campaign to get New York Governor Andrew Cuomo to support bail reform. Sheldrick says Global Citizen users have placed about 7,000 phone calls to his governor's mansion over the last few months. Though Cuomo recently proposed regulations to crack down on "predatory practices" in the bail bondsman industry, those did not address eliminating cash bail, which many activists, including Global Citizen, point to as a major issue. (According to the Governor's website, some areas regarding cash bail reform are still on the governor's criminal justice agenda.)

A new approach

An educational trip to the Philippines from his home in Melbourne, Australia put Hugh Evans, now 35, on the path toward launching Global Citizen. It was there, in the slums of Manila, that he met a local teen named Sonny Boy who lived in poverty. The encounter helped him see his own comfortable life was largely due to luck. "Just lying there that night it struck me that it was pure chance that I was born in Australia and Sonny Boy was born there," he previously told CNBC. "We don't deserve, or we have no entitlement to the lottery of life that we have." (He won "the ovarian lottery" as billionaire Warren Buffett calls it). In university, Evans organized a charity music concert that attracted the band U2 in its first year and soon drew international attention. In his 20s he started a charity to build schools and traveled the world. Evans continued on with the concerts, but the more he fundraised and the more he learned, it became clear that poverty was a systemic problem. "We realized, you know, that no amount of gala night dinners or charity quiz nights is what's going to end extreme poverty," he said. To take a different approach, he founded Global Poverty Project in 2008, which started the Global Citizen platform. The idea to gamify came in 2011 when co-founder Ryan Gall suggested a concert for which the non-profit could distribute tickets, not in exchange for money, but in exchange for people taking action. "We needed a sustainable movement," Evans recalled in a 2016 TED Talk.

Digital activism as an answer