For CCBILL only:
Multi-sign – multiple transactions from individual consumers can be processed and accepted within a short period of time, enabling them to receive additional access to content.
One click upgrades (ChargeByPrevious) – an excellent option for the live entertainment business model, CCBill One-click Upgrades let you offer a simple way for consumers to purchase additional content without having to repeatedly enter in their billing information.
The reason we ask for both in this case is so that if a customer goes ahead and clicks a "Buy Now" on a couple videos one after the other, it won't automatically decline them. Also, it won't ask for their credit card number again and again between orders.
The system can work without these in place, but from a user perspective, it isn't as friendly.