From Skybook Website.
Cash Bonus Policy
If a cash bonus is awarded, no withdrawals will be allowed until the predetermined rollover requirement has been met. For example, a $500 deposit receives a $50 bonus. The rollover, which includes the bonus amount, is 4x. Therefore, $2,200 is the total amount required in sports wagering action prior to withdrawal of any portion of your balance.
In order to meet our new money requirements, if a customer withdraws funds from an account, the customer must deposit funds exceeding the withdrawal amount before cash bonuses are issued again.
If you deposit more funds prior to meeting the previous deposit’s rollover requirement and take another bonus, the following formula will be applied to determine your next deposit’s rollover sum: Deposit Sum + Bonus Sum + Pending Wager Balance + Current Account Balance x Rollover Requirement
Once a bonus is accepted it cannot be forfeited.
http://www.skybook.com/rules_and_regulations.asp
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