The bookmakers are always considered to be doing something wrong and they take money from both bettors. This false idea has been spread due to the dealing some fake bookmakers whose sole interest is in making money.
Actually a bookmaker can accept only a small amount as commission from the losing bettor.
This will be fair enough since both bettors are treated in the same manner. The person who wins will lose only a small percentage of the amount he actually gains and the losing person already knows that he will lose the complete amount on failure.
There are situations when some bookmakers willing to take more risk to capitalize certain situations. The amount for bet is made equal so that everyone participating in the bet will have to take same amount of risk and can lose only same amount of money, but this won’t be beneficial for the bookmakers. In some situation a very strong team may be playing the weakest team. The ethics of the bookmaker will have work here play fair on people betting on both sides. More people will naturally prefer the strong team since the chance for them to win is more. So amount at stake is set to a very large amount and this process is called shading. The bookmakers may sometimes give different prices to different people for betting. The customer will use his previous experience in sports betting to increase his possibility to win based on the choice of pricing.
The bookmakers have to be extremely careful in dealing with point spread bets.
The line of spread may tend to move based on the no of people involving in a bet. If a line of spread move from 27 to 29 and if the favorite team wins with 28 points then the bookmaker will have to pay all the customers.