^^^ If he doesn't invest, how will he get money to donate?
While there is no doubt that Bill is saving millions of dollars this way which would've otherwise been written off as tax, we must also not forget that 10% (of what!!??!! thats teh huuuuge amount!) is really going in for humanitarian benefit. I guess two members here haf a problem with the term "philanthropist"... fine don't use it.. and close this useless topic! But if someone says that those 10% spent as donation is not useful for the betterment of mankind then that person is surely insane.