This is why we can't have nice things. Now they'll face a lawsuit, costing zillions. They'll pass the costs onto the consumers in the form of a higher vig. Books taking 10% on losses is how they stay in business. So what Whaler is saying is they more or less make 5% on every bet made (there's some disagreement as to exactly how they arrive at those numbers, but for the sake of argument take it as truth). With small margins like that, I don't see a "legal" book being able to survive unless it's tied in with a larger operation that can absorb the losses and offer other ways to lose your money like the casinos.