Just to let the community know the facts:
I decided to try BitBet.us, put in 0.02 BTC just for the fun of it. I've chosen a bet about BTC difficulty, more than a week before closing while the result was far from obvious, in fact there was one much bigger bet on opposite outcome after mine.
Bet details:
http://bitbet.us/bet/454/btc-network-difficulty-tops-25-million-by-end/Bet TX id:
https://blockchain.info/tx/e28963e5183ccf2c13ffbb3e41857ccaf53b1a6679d3453c5772b6d65786f7c6It was fairly balanced bet, 124.78 BTC on winning side and 43.58 BTC on losing side, Weighted Winning: 2`891`58, Weighted Losing: 2`568`92.
Still, BitBet.us calculated:
BTC IN: 0.01966650, BTC OUT: 0.01954554
I won that bet, and got less money than I've put in?!? What kind of nonsense is that?!?
If you can win a bet and lose money on balanced bet long before closing, think what would happen on late unbalanced bet.
Of course, I've sent an email to BitBet.us a week ago, asking politely for clarification, guess if I got any answer from them. You guessed right. Avoid BitBet.us in a big circle.