Since the cost of maintaining a virtual currency is extremely small, there is no practical limit. Of course, some small number will dominate. For a parallel situation, look at home many Linux distros there are: http://en.wikipedia.org/wiki/Lis... That can occur because one person, with enough free time, can package there own distro. But a handful of all distros represent the majority of all Linux installations.
According to the figures in the infographic Bill Gates has given $28 Billion to various charities since 2007, which apparently accounts for almost 48% of his net-worth. One of his biggest charitable efforts has been towards the eradication of malaria and an end to polio.
Gates will then work part-time at Microsoft (up $0.19 to $22.07, Charts) as chairman and technical adviser and will work full time for the Bill and Melinda Gates Foundation, the organization he founded with his wife, which focuses on global health and education.