When Sameer Bhatia, a 31-year-old Stanford graduate and Silicon Valley entrepreneur, was diagnosed with leukemia, doctors told him he had a one in 20,000 chance of finding a suitable bone-marrow donor.
Knowing those odds, his friends made it their goal to register 20,000 South Asians in a bone-marrow registry. Using social-media tools such as Facebook, Twitter, and YouTube, as well as traditional means, they managed to register 24,611 donors in a matter of weeks.
The Dragonfly Effect chronicles that effort. The book's co-author, Jennifer Aaker, says the success of Mr. Bhatia's story illustrates two essentials for social-media campaigns: Set a single, concrete goal, and never underestimate what a powerful narrative can do.
In the latest episode of Social Good, Allison Fine, the host, discusses these ideas with Ms. Aaker, a Stanford University business school professor.
Social media may make it easier than ever for more people to get involved in a cause, Ms. Aaker says, but it takes good stories to motivate people to act.