One issue encountered by SaaS* (Software as a Service) providers is what to do when your subscribers' credit card expires or is re-issued for some other reason (eg the card gets lost).
Once the original card is cancelled, next time your website tried to automatically charge the custoemrs card, it would most likely fail. This would mean your system would then need to email the customer, to let them know their card failed and to log in a enter in their new credit card details.
Many customers would see this a nuisance; I know as a customer myself to many SaaS offerings, having to log in and update X number of websites with my new credit card details is a royal pain in the #@%#$%!
However, one company, Stripe, has managed to change the way expired/replaced cards are dealt with (the eCommerce/SaaS websites we build for our customers all use Stripe).
When your website uses Stripe to process your customers' recurring credit card payments, any expired or replaced cards will automatically be updated to the new card details, thanks to the relationahip between Stripe and the credit card networks.
Your customers won't need to log into your site and enter new card details. This helps keep customers with your service, reducing customer "churn" (which is the rate at when you lose customers from your website).
If you're looking to build a SaaS based website, talk to us about using Stripe as your payment platform.