When you win and beat a book, are you still proving a service to that sportsbook? By betting you are creating liquidity in the market. If I move the line from -110/-110 to -115/-105, it means more action should follow on the -105 side and the book stands to make money.
I look at this like traders that do high frequency trading. While they take equity out of the system they also provide the service of liquidity.
I look at this like traders that do high frequency trading. While they take equity out of the system they also provide the service of liquidity.