Facebook founder and billionaire CEO Mark Zuckerberg and his wife Priscilla Chan have promised to give away 99 percent of their Facebook shares to help charity via their philanthropic organization, the Chan Zuckerberg Initiative.
Running the Initiative of course means working together. Though Warren Buffett says who you marry is crucial to success, working with a significant other or family member isn't always easy.
So what's their secret to a happy professional and personal partnership?
"A lot of people ask us what it's like to work with your spouse," they write in the letter published Wednesday with updates on the Chan Zuckerberg Initiative.
"The reality is we have very different experiences, as a doctor and educator, and an engineer and executive — so we learn a lot from each other," says the couple.
They've also made some helpful rules, "like not talking about work right before bed," according to the letter.
Though they have their differences, both are relentlessly optimistic, and that, they say, keeps them in lockstep.
"What makes us a good team is that we're both optimistic about the future at a time when a lot of people don't feel that way. We believe there are answers to even the toughest problems, and one of the things we're most proud of is that we've built a team that believes that too," the couple write.
The two met at Harvard, as Zuckerberg reminisced in a commencement speech there:
"My best memory from Harvard was meeting Priscilla. I had just launched this prank website, Facemash, and the ad board wanted to 'see me.' Everyone thought I was going to get kicked out. ... My friends threw me a going away party. As luck would have it, Priscilla was at that party with her friend. We met in line for the bathroom ... and in what must be one of the all time romantic lines, I said: 'I'm going to get kicked out in three days, so we need to go on a date quickly.'"
Zuckerberg didn't get kicked out, and the two started dating. In 2012, they got married and now have two daughters, Max, born in 2015, and August, born this summer. (Zuckerberg is currently on parental leave from Facebook.)
Wednesday's letter also explained more how the couple plan to use their fortune. Zuckerberg is currently worth almost $73 billion, according to Forbes.
First, they will help "the most talented leaders take on challenges in education, science, justice, and economic opportunity over 10 or 20 years, rather than just focusing on the biggest issues of today," the two say.
Instead of focusing on the logistics of providing healthcare, for example, their foundation will focus on preventing and curing disease in the first place. Instead of focusing on charter schools versus public schools, the Chan Zuckerberg foundation will focus on giving all teachers access to the tools they need.
Second, the initiative will focus on investing in philanthropies powered by technology.
"The magic of technology is that it can help social change scale faster," the power duo say. And because of Mark's experience building a world-class engineering organization at Facebook, "we are in a unique position to build a philanthropy with a great engineering team to help our partners scale their social change faster as well."
Specifically, the Chan Zuckerberg initiative will concentrate in three areas: improving education, advancing science and fighting for justice and opportunity.
In addition to being the co-founders of the Chan Zuckerberg Initiative, Zuckerberg and Chan are signatories on The Giving Pledge, a commitment kickstarter by billionaire buddies Bill Gates and Warren Buffett inspiring billionaires to give away their wealth to charity.
Like this story? Like CNBC Make It on Facebook.