ProductCart v4.1 and above include built-in support for Early Impact's new recurring billing system. In your ProductCart-powered store you can now easily flag a product as a subscription, and - when an order is placed - a recurring payment profile is automatically created.
SubscriptionBridge takes care of managing the subscription from then on, making it easy to do things like:

We recently improved the integration between ProductCart and SubscriptionBridge so that you can now sell, at the same time, a product/service that requires recurring payments (e.g. service contract, extended warranty, club membership, etc.) and one-time purchase items.
For example, on the Early Impact software store you can purchase, at the same time, a ProductCart license (one time purchase) and a Technical Support Plan (recurring billing item). Note: there are some limitations to this feature. See the ProductCart - SubscriptionBridge integration documentation.
SubscriptionBridge works on top of popular, robust recurring payment systems such as Authorize.Net's Automated Recurring Billing (ARB) and PayPal's Website Payments Pro recurring payments. It adds a tremendous amount of features (e.g. see what it adds to Authorize.Net's ARB system) that are focused on:
