Whether the odds are high or small the house will always win in gambling in the end. This is all about business because this will make them keep on operating and they are not going to build gambling site that is not in favor of them. And always expect that if you are an addicted gambler, you'll just lose in the end or if you can win, very minimal percentage.
If the odds is high, that means your 'real' chance of winning is actually small although theoretically it still means 50 %, either you win or lose. The house doeant always win in the end however they will win in the long run on average and people just cant really tell the difference of these statements