See also: Wikipedia on gambling as a stupidity tax:
http://en.wikipedia.org/wiki/Lottery#Expected_valueLotteries are sometimes described as a regressive tax, since those most likely to buy tickets, and to spend a larger proportion of their money on them, are typically less affluent people. It is also often referred to as a voluntary tax. The astronomically high odds against winning the larger prizes have also led to the epithets of a "tax on stupidity" and a "math tax" (or both epithets combined gives "tax on the mathematically inept").
As others have said, you should really quit while you're ahead.