We care deeply about the safety and security of our customers personal information. To comply with the best and safest industry security practices, we work with Braintree, a popular payment processor. To meet PCI Compliance guidelines, Grokker cannot see or store payment information. The information is encrypted on a subscriber's computer and then sent to Braintree. Grokker does not have access to the encryption keys - this is all handled by Braintree.
When a customer subscribes, their encrypted credit card information is securely stored by Braintree on their servers (which regularly undergo security screening). When a user cancels their subscription, the payment information remains stored. This makes it easier to take advantage of a sale at a later time. The payment information can be removed from Braintree's servers via a button on the Settings page, but only after user is no longer subscribed.