Subscription-based sites face a number of challenges around billing, such as:
- Automatically charging cards every month
- Requesting new credit card information when a card has expired or a charge fails
- Safely storing (or outsourcing storage) of credit card information
- Providing historical invoices
- Coupon codes followed by normal billing cycles
...as well as many other challenges. The typical solutions for e-commerce (Drupal Commerce or Ubercart) in Drupal turn out to be extremely heavy and wildly complicated. The Recurly module and associated service eliminates the most difficult problems by outsourcing them to a dedicated service, but at the same time provides a seamless interface so users are unaware of it being used at all.
Come and check out this excellent payment solution and the tight Drupal integration provided by the Recurly module for Drupal.