He should know. Since its founding in 2006, charity: water has brought clean water to 7 million people around the world, about 1% of the estimated 663 million whose drinking water carries disease or is otherwise unsanitary.

Harrison, a former nightclub promoter who was on Fortune’s 40 Under 40 list in 2011, saw an opportunity gap in the charitable giving space, where nearly half of donors say they don’t trust that their donations are actually being put toward the cause. At charity: water, 100% of contributions go to clean water projects such as well-drilling and filtration.

Charity: water has been a hit from the start. In its first year, it brought in $1 million donations. Over the past decade, 1 million people have given $250 million, mostly in small amounts of between $10 and $50.

In the past decade, Harrison has also upended the standard charity donation model, using social media, including LinkedIn, Twitter, and Facebook to get the word out and collect funds, as opposed to more standard mailing lists. Additionally, the organization has a separate budget to fund its operations, primarily through a network of wealthy entrepreneurs that includes Michael Birch, founder of social media network Bebo.

Check out the video above to find out more about how charity: water has courted the tech world for donations, even as it depends on grassroots giving.