Originally Posted by Kiopa_Matt

Allow affiliates to pay themselves out, and charge a small fee depending on payment method. You want PayPal, it's $2.50, Western Union is 4%, and so on. Hold newly made commissions for X days, then lessen that restriction as the affiliate proves himself to be in good standing.

Then just let affiliates choose when they get paid. When they want, they login, and submit a withdrawal request.