If online casinos accept PayPal, the most convenient method to withdraw would be back to this e-wallet as well. Some online casino registers prefer some methods to others, so if you have any other payment methods registered, they might transfer your withdrawal there as a priority. This is often the case with bank accounts. However, if you have no other methods registered in an online casino, use a PayPal to deposit, and then decide to withdraw to (for example Skrill) and add Skrill at that moment, you might have to withdraw to PayPal that one time. A certain payment method has to be registered and approved in your online casino account at the time of your depositing with PayPal so you would be able to withdraw to it.