Customer vaults are a great way to ensure that sensitive cardholder information is safe and secure.
Merchants should never store unencrypted customer credit card or bank account information on their computers. Even if encryption is possible, it's better not to store it at all on the merchant's computer. It's best to leave the storage and security issues to companies that have the technology and security experience to safegaurd valuable customer information. Fortunately, gateways like Network Merchants and Authorize.net allow just that.
The Network Merchants Customer Vault allows a merchant to store credit card or electronic check information on Network Merchant's servers. The intial entry and storage can be accomplished through a web-based application or it can be accomplished via a secure API. Once the information has been stored, it can be used for future payment transactions using the virtual terminal or API methods.
Authorize.net CIM (Customer Information Manager) works in a similar way except that CIM customers and billing profiles can only be stored and used via API methods.
All in all, the Network Merchants Customer Vault is more flexible than the Authorize.net CIM service since it supports non-API access methods in addition to API access.
Services like Network Merchants Customer Vault and Authorize.net CIM are very useful for recurring billing applications in which the billed amount changes from month the month (or over some other period). If the billed amount is the same each period, then a more standard recurring billling service might be appropriate. However, if the amounts change each month, then the merchant can take advantage of the secure storage services provided by the vault while changing the amount billed each month.