Volumes are not huge like in finance, you will lose more on the bet that you will make back in your marginally improved odds.
> I guess they try to cream the most addicted people, seems quite intuitive to me.
The professionals, not the addicted. The addicted expire quickly and they typically don't use exchanges anyway.
The logic of bookies is simple: Don't do business with people who win more than they lose.
It doesn't matter how the customer is getting an edge. A brilliant algorithm? A complex arbitrage system? Deep insight from years studying the sport? Cheating? Time travel? The bookies don't care.
The only thing that matters is, if you win more than you lose you've got some sort of edge. And if you've got any sort of edge, it's more profitable not to do business with you.
Some of them ban outright and some restrict your stake. When I worked for a bookmaker we had an account that had made several hundred thousand £s from us and was limited to betting relatively small amounts. He would always bet as soon as our odds would open and then we'd adjust them.
Why don't they just use those people to adjust their odds faster for everybody else ? Or do they limit the size you can bet rather than just banning you ?
> I also found out that the more you bet, the more percentage commission you pay to exchanges like Betfair, which is quite contraintuitive - commission goes up with volume, not down.
I guess they try to cream the most addicted people, seems quite intuitive to me.