I consider it to be more like a gamble than ponzi scheme. Since you know from beginning that you could lose your coins.

It's a gamble that you have pretty much no control of...
I would say it's a ponzi scheme, and plus these things will always turn out badly.

Not really.
When you play satoshi dice, you know that you are loosing money, but there is a chance than you make profit

It is the same here, maybe someone will buy it and give you some profit, or maybe you will lose your btc