I'm no fan of Bill Gates, but give the guy his due:

Bill Gates contributes $1 billion to charity "Microsoft Corp. Chairman Bill Gates and his wife are donating $1 billion over the next 20 years to finance college scholarships for minority students"

Bill Gates' charity becomes second largest in the world "Microsoft founder Bill Gates will donate an additional $6 billion to fund research into developing new vaccines for diseases that disproportionately affect the developing world"

Gates donates $5B to Gates charity "Bill Gates and his wife, Melinda, have donated $5 billion in Microsoft Corp. stock to charity -- the largest gift ever given by living donors to a philanthropic group."

A summary of Gates' charitable donations "Before he began giving money away, people complained that he was a miser. Now that he is giving money away, they complain that he’s doing it too late, that he isn’t giving enough, that he hasn’t a clue about what he’s getting into, that the projects he is financing are too conservative, too liberal, too big, too small, too safe, too risky, too conventional, too splashy"

It doesn't really stand up to logic, but to use your own analogy Gates' donating $6billion is like a normal person donating $6,000 (if they earn $60,000, and gates is worth $60bn). And that's a pretty hefty charitable contribution...