Mark Zuckerberg and Priscilla Chan made headlines this fall when they pledged to donate 99% of their monetary wealth to charity throughout their lifetimes. The couple joins a myriad of other billionaires who have made public pledges through Bill Gates’ and Warren Buffett’s “The Giving Pledge.” While the site explains there are no legal commitments inherent in these pledges, each donor(s) wrote a pledge letter that is attached to their profile on the website.