hello,
could you please explain me what doet it mean
Is there any additional fee of the Proof-of-Stake Service?
Yes, service will charge a 2.5% fee from the vote reward (~ 0.04 DCR / ticket) of every user, which will be distributed between all EFT token holders (you can buy them in the Exchange, if you want to have that additional passive profit).
if you buy a ticket for me , you will charge 2.5% fee from me? like a rake in poker?
what happened if I (you) buy 100 tickets for me and no one will win? then I lose my DCR.. or?
This fee is charged from your vote reward (which is currently ~ 1.50 DCR), not from the ticket price (so it's not like rake in poker, which charged from total amount. Instead EVO charges fee only from "the money you won")
If you will purchase 100 tickets - you will pay only transaction fees to PoW-miners (as for any other crypto transaction, but the fees for tickets are much much higher due to high competition).
However, note that every ticket has ~ 99% chances to cast a vote during its lifetime of 142 days. Average vote time is 28 days per ticket (so if you purchase 30 tickets, you can expect in average 1 voted ticket per day). Expired rate usually as low as < 1%. In this case you receive your money back without vote reward (and without transaction fee which you paid to PoW-miner when you purchased ticket)
.