I am helpless that you are unable to differentiate between honesty and ethics.
Being honest about something does not make it ethical or legal. (refer the thief question. Think if it was more serious than money. like life.)
if you want to talk about ethics: i think providing gambling (casino dicesite etc) is unethical too (except if playing with friends about little money).
please just tell me what is the difference between an honest and open ponzi and a lottery except that with a ponzi the odds get lower over time and stay constant with a lottery?
both WILL make most persons loose money.