How Charities Harness Social Media

Mr. Harrison is the founder of Charity: Water, a nonprofit dedicated to bringing clean water to impoverished villages in Africa. In January, he got an e-mail from a British woman who wanted to test Twitter as a fundraising tool. Amanda Rose thought the microblogging site, with its 30 million users, might have some cash power, and if it did, she wanted to put the cash in Harrison’s wells.