and lorinda gates is the co-chair of the bill and lorinda gates foundation. >> it's a tricky issue, i think for anybody who's leading in any arena. the foundation is actually in about 24 different topic areas if you take them from vaccines to family planning to trying to lift and empower people. i follow my passion and also the data. i look to see where the greatest need is, but i also listen very carefully when i travel. so i travel to the developing world a lot. i go in as anonymous woman from the west, in a pair of khakis and a t-shirt and i listen to women. and i hear from them, when i hear what matches the global data, that's what i act on. >> i talked to women about vaccines, and they said wait a minute, what about the shot that in the arm that i get. it's a life and death crisis, i go to the clinics, it's not there, why not? and i came home and started studying the global statstatist -- >> there's to many great ideas, but we only can do a few really well. so at facebook, what we really focus on is how people share, and making that sharing experience better. that's taken us from