The only role other than paying their taxes, whatever those are, the only role for philanthropy broadly - of which the rich should give disproportionately - the more, the better - and I think there is a positive trend in that direction - there are certain risk-taking things, like trying out a new type of charter school or funding a new kind of medicine.

Customer service will become the primary value added function of every business.

Africa is on the rise.

As we have taken diarrhea and pneumonia down, even malaria down quite a bit, the portion of the days that are very early in that 5 years - the first month, the first day - it's about half now. Yet that's the part we understand the least.

I have seen firsthand that agricultural science has enormous potential to increase the yields of small farmers and lift them out of hunger and poverty.

Paul and I, we never thought that we would make much money out of the thing. We just loved writing software.

Money has no utility to me beyond a certain point.