I have great admiration for Bill and Melinda Gates and Warren Buffett and their recently announced effort to convince/cajole their fellow billionaires to follow their lead and pledge to give at least 50% of their wealth to charity. I was especially moved by Mr. Buffett’s letter explaining his reasoning. It speaks very directly to many of my own motivations and thinking around philanthropy.

And yet….and yet….

Imagine if Bill Gates used the power of Microsoft to push for an end to conflict minerals (which, like conflict diamonds, are often mined using slave labor and used to funnel “legitimate” dollars to armed militias terrorizing local people in Eastern Congo), insisting that only “conflict-free” minerals be used in computers and other electronics featuring Microsoft Office.

Imagine if Warren Buffet insisted that every company in which he is a shareholder provided a decent paid family leave and established benchmarks for increased diversity among upper management.

Imagine if Oprah Winfrey decided that only companies who certified their supply chains as free of child labor would appear on her television show or the new OWN Network.

Imagine if…the world’s billionaires became active philanthropists. Not the kind who give money away—for me that earns you the title of “donor” but not necessarily “philanthropist.” Rather, the kind who use all of their assets—their power as consumers, investors, public figures and role models—to really bring about social change on a mass scale. The combined impact of increased social responsibility from the companies they could influence would dwarf the power of their charitable dollars funneled through nonprofits.

…Manufacturing companies seeking computer parts would be motivated to find other sources of minerals and effectively close off a critical funding stream and thereby cripple the armed militias of the Congo.

…Tens of thousands of women struggling to balance work and family would enjoy improved health for themselves and their babies, and their companies would save the time and expense of replacing them.

…Companies with fair supply chains would be the ones to receive the benefits of “The Oprah Effect” and others would be incentivized to clean up their labor practices if they wanted to join in. Millions of children around the world could be affected, reducing child trafficking and forced labor as these practices become increasingly unacceptable to American consumers, led by the millions who are loyal fans of Ms. Winfrey.

Don’t get me wrong, we need the nonprofit sector and the many important charities doing great work all over the world. I’m not suggesting people shouldn’t give money to charity. But for the world’s billionaires, believe it or not, money is not their greatest asset. It’s influence. That influence in part comes from their billions, and so giving away their money should not be a substitute for using their influence to bring about positive social change. (And as Phil Cubeta points out, “good” people giving away their billions leaves the “selfish, controlling, manipulative SOBs” to built dynasties and eventually rule the world.)

So let’s applaud the Gates’s, Mr. Buffett and the others who have already pledged their wealth to charitable causes. But let’s also applaud the growing class of social entrepreneurs who start or work for businesses that don’t make them billionaires but do provide sustainable livelihoods, environmentally friendly products and social justice along with financial returns.