It depends on when you place the bet.

> House Fees: To encourage betting early, house fees begin at 0% of your bet and increases linearly to 20% when the betting round closes.

(http://www.futureblock.com/how-it-works)

Well.... not really.

Parimutuel betting, not sure - but there is always a house fee - that's how the house makes money.

A traditional bookie would have at least 5 to 10 % built into his odds as well (like if you were betting on even odds, liek a coin toss, it would be bet $110 to win $100 for either side (so the bookie has a 5% hold if he can keep the betting balanced, no matter who wins)

etc etc.

In this case, there is 0% fee if you bet when the round opens.

I think the bootstrapping is worth more than getting an initial basefee, since it'll likely bring more players, making it worth it towards the end.