When Facebook introduced a feature that enables people to register to become organ and tissue donors, thousands did so, dwarfing any previous donation initiative, write Blair L. Sadler and Alfred M. Sadler, Jr., in a commentary in Bioethics Forum, the blog of the Hastings Center Report, which analyzes the "Facebook effect" on donation.

The Sadlers, Founding Fellows of The Hastings Center, helped draft the Uniform Anatomical Gift Act, established in 1968 to standardize state laws on the donation of organs and tissue after death. Blair Sadler, a lawyer, is a member of The Hastings Center's Board of Directors. Alfred Sadler is a physician.

Their commentary tracks the response to Facebook's introduction, on May 1, of a feature that lets people state their wishes to become donors in an attempt to reduce the long waiting lists for organs and tissue. "By the end of the day of the announcement, 6,000 people had enrolled through 22 state registries," the Sadlers write. In California alone, 3,900 people signed up, compared with 70 on a typical day.

After two weeks, the rate of registration returned to previous levels, but the Sadlers suggest several strategies for harnessing the full potential of social media to achieve a sustained increase in registration. "Perhaps missing is the repeated cuing that can help drive individual action," they write. "An annual day to celebrate registered organ donors would be one way to enhance cuing. Asking state donor organizations to provide Facebook with real-time updates on the growing number of registered donors might be another."

"State registries could include social sharing on their sites, so that once a person joins the registry, he or she has the option to share this information via Facebook, Twitter, and other social networks which should drive awareness among friends and family," they write

The Sadlers also suggest that social media companies allow donor registries to advertise at no cost. "Facebook has challenged other technology companies to show corporate leadership and has demonstrated the power of social media to encourage altruism."