It's definitely a ponzi. The question is if it will collapse before your payout or not. Very risky game.
150 doge is not that much, but don't 'invest' more than this.
i think this system cant live 4 more days
but 150 doge is very small prize
so if u want, u can try for fun
but as i said, it has high risk

If they are usig that 18k BTC stolen from Bitstamp, they can live few weeks or so.
So, they will making even more money.