Simple to write "scam". It's not a scam, it's a gambling. and we are much more honest of another similar services.
1. we refund the TX over the maximum (another services consider it like a donations)
2. when round change, the "bank" balance remains available on the new round (others take it)
3. when a round near to close you can start over with a 0.001 tx and wait more opportunity. This feature give to the round to never going stuck.
1. Useless. Waste of time.
2. Useless. There is not much btc in the end of every round because it is paid.
3. Useless. Last persons in such ponzi always loose.