The tool they use is called niche crowd-funding. Entrepreneurs set up websites for very specific types of charitable projects, like supporting small farmers in developing nations or helping victims of natural disasters. People who need backers can put fund-raising pitches on the site—and the entrepreneurs take a cut of whatever money they raise.
The sums involved are usually modest. Users generally donate about $20 to $100, and most projects don’t have big funding goals. Still, many of the site owners aren’t looking for a big payoff—they see themselves as social entrepreneurs whose first priority is helping others.