Last week Facebook became the first company to invite users...

Last week Facebook became the first company to invite users to register as organ donors. Credit: Facebook

Facebook Inc. took a momentous action last week. And I don't mean its announced intention to sell shares for $28 to $35 in an initial public offering later this month. The company invited users to register to become organ donors.

Forty-eight hours later, more than 100,000 people had indicated, on Facebook Timeline, their wish to be a donor when they die. As a result, online state donor registries experienced a 23-fold surge, according to Donate Life America.

For the 114,000 people waiting for a kidney, liver, heart or lung -- 7,000 to 10,000 of whom die each year -- Facebook has performed a great service. For more than two decades, advocates have been urging people to sign up as donors when they renew their driver's license, yet only about 43 percent have done so. Facebook has made it much easier.

And although this impressive achievement won't be enough to fill the great demand for transplantable organs, it may also help show the way forward to encourage live donations.

Facebook's strategy allows people to announce to their friends what they've done, encouraging them to become donors, too. Many studies have shown that information about people's decisions to perform a public good can persuade others to follow suit. Given Facebook's reach, the site might be able to amplify positive peer pressure and drive awareness more powerfully than standard public-health appeals do.

Organ-donation groups are rightly thrilled with Facebook's initiative. Yet it's important to keep the larger picture in mind. Even if every American agreed to be an organ donor, there still wouldn't be enough kidneys for transplantation.

I specify kidneys because people with renal failure represent about 80 percent of those on the national organ waiting list. Last year, roughly 91,000 people needed a renal transplant, but only one-fifth of them received one.

Now look more closely at the donor math: Of the roughly 2 million Americans who die annually, only an estimated 10,500 to 13,000 possess organs healthy enough for transplanting. If every eligible person donated his organs at death, surgeons might be able to double the number of transplants. Without doubt, a deceased-donation windfall would shorten the time some people languish on dialysis, and it would prevent the premature deaths of others.

But a "shadow list" of ill people is waiting in the wings. These are patients on dialysis who could benefit from transplantation, but whose doctors have never referred them for the surgery. Jesse Schold, an epidemiologist at the Cleveland Clinic, estimates this pool to number from 80,000 to 130,000 people. Thus, the true waiting list may be double its current size. The supply of organs from the deceased will never be enough.

So can the Facebook initiative be leveraged to increase living donation?

Deciding to give a kidney while alive to a loved one, let alone a stranger, is very different from checking a box that instructs medical professionals to take your organs when you're gone. (I received a kidney transplant from a living donor.)

What's needed to complement Facebook's breakthrough are rewards for living donors. These could take many forms: perhaps a contribution to a retirement fund, an offer of lifetime health insurance, a tuition voucher or a large charitable contribution in the donor's name.

In-kind rewards such as these would not attract desperate people who might otherwise rush to donate for a large sum of instant cash. Living kidney donors would be carefully screened for physical and emotional impediments to safe donation and be guaranteed follow-up medical care for any complications.

Right now, such incentives are illegal. The 1984 National Organ Transplant Act considers any kind of donor enrichment a felony. But with ample public support, that law could be changed to allow pilot trials.

Facebook's donor sign-up is a brilliant way to harness the power of social networks to save lives through donation after death. Next, perhaps the social-media giant can add another status question that allows people to "like" the idea of rewarding people who are willing to give a kidney and save more lives -- and tell their friends.

Dr. Sally Satel, a resident scholar at the American Enterprise Institute, is the editor of "When Altruism Isn't Enough: The Case for Compensating Kidney Donors." This is from Bloomberg News.